Modular defibrillator architecture

ABSTRACT

Several defibrillators, defibrillator architectures, defibrillator components and methods of operating defibrillators are described. In one aspect, a modular defibrillator architecture is described. A base unit provides a fully functional defibrillator. The functionality of the base unit can be supplemented by attaching an interface unit to the base unit or by connecting a smartphone the base unit. Such devices provide connectivity as well as a screen for displaying supplementary graphics and/or videos which are useful to support both emergency and maintenance &amp; monitoring activities. In some embodiments a battery pack may also or alternatively be coupled to the base unit to prolong the unit&#39;s shelf life before recharging or replacement of its batteries is required. If necessary the base unit can be powered from a connected external device such as a mobile communication device.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the priority of U.S. Provisional PatentApplication Nos.: 62/566,896 filed Oct. 2, 2017; 62/576,228 filed Oct.24, 2017; 62/615,533 filed Jan. 10, 2018; 62/617,400 filed Jan. 15,2018, 62/652,193 filed Apr. 3, 2018; and 62/674,711 filed May 22, 2018;each of which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present disclosure relates generally to modular defibrillators andmany of the inventions described herein are particularly applicable toautomated external defibrillators (AEDs).

BACKGROUND

Sudden cardiac arrest is one of the leading causes of death. In theUnited States alone, roughly 350,000 people die each year from suddencardiac arrest. It is the leading cause of death for individuals over 40and the #1 killer of student athletes. The most effective treatment forsudden cardiac arrest is the use of CPR coupled with defibrillation.Automated external defibrillators (AEDs) are portable devices designedto automatically check for life-threatening heart rhythms associatedwith sudden cardiac arrest and to send an electrical shock to the heartto try to restore a normal rhythm when shockable heart rhythms aredetected. The two most common conditions treated by AEDs are PulselessVentricular tachycardia (aka VT or V-Tach) and Ventricular fibrillation(VF or V-Fib). AEDs are typically designed such that they can be used bya lay person in situations where professional medical personnel are notavailable.

Given their potential to save lives, automated external defibrillatorshave been deployed in a relatively wide variety of public and privatelocations so that they are available in the event that a person in thevicinity goes in to cardiac arrest. By way of example, AEDs may be foundin corporate and government offices, shopping centers, airports,airplanes, restaurants, casinos, hotels, sports stadiums, schools,fitness centers and a variety of other locations where people maycongregate. Although the availability of AEDs has increased over theyears, their relatively high cost tends to limit their placement andmany locations including schools, sports fields, and a plethora of otherplaces where people congregate don't have an on-site AED available.Furthermore, although many AEDs are considered “portable”, mostcommercially available portable automated external defibrillators arebulky and heavy enough that they are rarely carried by people other thantrained medical personnel. Thus there are many times, locations andevents where no AED is available when a cardiac arrest incident occurs.Even when an AED is nearby when a sudden cardiac arrest incident occurs,the AED is often not used because either its presence is unknown or thedevice seems intimidating to bystanders who are reluctant to try to usea device that they are unfamiliar with to treat a medical situation thatthey are unfamiliar with.

Although existing AEDs work well, there are continuing efforts todevelop AEDs that have characteristics likely to broaden the deploymentand availability of automated external defibrillators.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention and the advantages thereof, may best be understood byreference to the following description taken in conjunction with theaccompanying drawings in which:

FIG. 1A is a diagrammatic illustration of components of a modularautomated external defibrillator in accordance with one embodiment ofthe invention.

FIG. 1B is a perspective view showing an interface unit attached to abase defibrillator unit.

FIG. 1C is a perspective view showing a mobile communication deviceconnected to a base defibrillator unit.

FIGS. 2A-2G, respectively, are perspective, top, front, back, bottom,right side and left side views of a representative base defibrillatorunit.

FIG. 3A is a block diagram illustrating electrical components of anembodiment of a base defibrillator unit.

FIG. 3B is a block diagram illustrating a charging power architecturefor a base defibrillator unit in accordance with another embodiment.

FIG. 4 is a block diagram illustrating components of a representativeinterface unit.

FIGS. 5A-5E, respectively, are perspective, top, front, side, and bottomviews of a representative interface unit.

FIG. 5F is a cross-sectional side view highlighting the interface unitarms matching the contours of the base unit to provide a secure formfitting attachment to the base unit.

FIG. 6 is a perspective view of an alternative interface unit housingdesign.

FIG. 7A is an exploded perspective view of a stacked defibrillatorsystem including an interface unit, a supplemental battery (charging)pack and a base unit in accordance with another embodiment.

FIG. 7B is an exploded perspective view of a stacked defibrillatorsystem including and a supplemental battery pack and a base unit inaccordance with another embodiment.

FIG. 7C is an exploded perspective view of a charging station and baseunit combination in accordance with one embodiment.

FIG. 7D is an exploded perspective view of a charging station and baseunit with an interface unit combination in accordance with anotherembodiment.

FIG. 8 is a flow chart illustrating a representative battery chargelevel check and management routine in accordance with one embodiment.

FIG. 9 is a flow chart illustrating a representative battery chargingcontrol flow in accordance with one embodiment.

FIG. 10 is a block diagram diagrammatically illustrating representativepower and data communication paths between a base defibrillator unit andselected modules that can be used in connection with the basedefibrillator unit.

FIG. 11 is a flow chart illustrating a process for synchronizinggraphics displayed on a connected external device with audio userinstructions issued by a base unit in accordance with one embodiment.

FIG. 12 is a diagrammatic representation of a defibrillator state table.

FIGS. 13A-13D are perspective, front, top end and second perspectiveviews respectively of a defibrillator having an interface unit mountedon a base unit in accordance with another embodiment.

FIG. 14 is a perspective view of the defibrillator of FIG. 13A with itspad cartridge partially pulled out.

FIGS. 15A-15B are exploded perspective views of the defibrillator ofFIG. 13A independently showing the base and interface units. FIG. 15C isa back perspective view of the interface unit alone.

FIG. 16 is a perspective view of a placard suitable for use with thebase unit of the defibrillator of FIG. 13A.

In the drawings, like reference numerals are sometimes used to designatelike structural elements. It should also be appreciated that thedepictions in the figures are diagrammatic and not to scale.

SUMMARY

Several modular defibrillator architectures, defibrillators, basedefibrillator units, defibrillator interface units, defibrillatorcomponents, methods of operating defibrillators and defibrillatorcontrol applications are described. In one aspect, a modulardefibrillator system is described that includes a fully functional basedefibrillator unit. An interface unit may optionally be mounted onand/or detachably coupled to the base defibrillator unit. In someembodiments, the interface unit has no substantial function other thanto operate in conjunction with the defibrillator but is not required forthe defibrillator to operate properly.

In another aspect, an interface unit is provided that includes aconnectivity module that facilitates wireless communication with aremote server. The interface unit may receive status information from abase defibrillator and forward relevant information to the remote serverto facilitate one or both of: (a) conveying information to emergencyresponders or medical personnel during an emergency incident; and/or tofacilitate routine maintenance and monitoring of the device. In someembodiments, the interface unit can also be used to facilitate thedelivery of software upgrades to the base defibrillator unit.

In another aspect the defibrillator may be configured to deliver audioinstructions to the user during use of the defibrillator and to transmitinformation to the interface unit and/or another external device (suchas a cellular phone or other mobile communication device) to facilitatethe display of graphical user instructions on the interfaceunit/external device that are synchronized with the audio instructionsprovided by the defibrillator. Such a feature may be used in bothemergency and non-emergency applications.

In some embodiments, the defibrillator is configured to provide at leastone of defibrillator state information and instructions to the interfaceunit and/or external device to facilitate the synchronized display ofthe graphic instructions on such devices. In some embodiments, thedefibrillator state information or instructions are periodically updatedto help ensure that the graphic instructions on the external device aresynchronized with the audio instructions provided by the defibrillator.In some embodiments, the interface unit and/or external device areconfigured to stop displaying the synchronized graphic instruction if anupdate has not been received from the defibrillator for a time periodexceeding a designated timeout threshold. In some embodiments, thedefibrillator state information or instructions are updated at afrequency of at least 3 updates per second to help ensure that thegraphic instructions on the external device are synchronized with theaudio instructions provided by the defibrillator.

In some embodiments, one or more defibrillator support applications areconfigured to execute on the mobile communication device and/or theinterface unit to control such devices to function in cooperation withthe base defibrillator unit.

In another aspect, the base defibrillator unit may be configured suchthat it will not utilize any control instructions from any attachedinterface unit or any other connected external device(s) duringemergency use of the defibrillator. To help facilitate this, theinterface unit and defibrillator support applications may be configuredto not transmit instructions or other information to the defibrillatorduring emergency use of the defibrillator. Conversely, the defibrillatormay be arranged to transmit information to any attached interface unitand/or a connected external device during emergency use of thedefibrillator.

In yet another aspect, a defibrillator includes a pair of connectors.The first connector is arranged to electrically couple an interface unitto the defibrillator when the interface unit is physically attached tothe defibrillator. The second connector is arranged to electricallycouple another external device to the defibrillator. In someembodiments, a defibrillator controller is configured to facilitatecommunications with an interface unit when the interface unit isphysically attached to the defibrillator and to facilitatecommunications with an external device when the external device isconnected to the defibrillator. In some embodiments, one or both of theconnectors are suitable for receiving power and/or facilitatingcommunications with their correspondingly attached device.

In yet another aspect, the defibrillator includes a battery charger (ormore generally a charge management module). The battery charger isconfigured to charge/recharge the defibrillator's internal battery usingpower drawn from one or more external devices. In some embodiments, thedefibrillator also includes a bypass circuit. The bypass circuit isconfigured to provide power received from the external device to acapacitor charging circuit in parallel with, or instead of, power fromthe battery to facilitate charging the defibrillators shock dischargecapacitor unit when the external device is connected to thedefibrillator during charging of the capacitor unit.

In some embodiments, the defibrillator the battery charger and thebypass circuit are both electrically coupled to a connector suitable forcoupling the defibrillator to an external device to facilitate receivingpower from the external device through the connector. In someembodiments, an inductive charging receptor may be used to receive thepower from the external device.

In some embodiments, the interface unit is configured to receiveself-test information from the base defibrillator unit and to report theself-text information to a remotely located server.

In some embodiments, the interface unit includes a GNSS sensor. Suchinterface units are capable of determining the location of thedefibrillator system using the GNSS sensor and reporting that locationto a remotely located server.

In some embodiments, the interface unit includes a rechargeable batteryand the defibrillator is configured to permit the interface unit batteryto be recharged at selected times when the defibrillator is coupled to acharger without drawing any power from the defibrillator battery. Insome embodiments, the interface unit does not draw any power from thedefibrillator during operation of the defibrillator.

In yet another aspect, a supplemental battery pack may be mounted on anddetachably coupled to the base defibrillator unit. In such embodiments,the defibrillator's battery charger is configured to utilize power fromthe supplemental battery pack to recharge the defibrillator's battery.

Corresponding methods are also described. For example, in one methodaspect, a defibrillator generates an audio instruction during emergencyuse of the automated external defibrillator. Information indicative ofthe audio instruction is transmitted from the automated externaldefibrillator to an external device having a display screen. Theexternal device then displays a graphic instruction on the displayscreen that is associated with the audio instruction during a timeperiod that is associated with the audio instruction. These steps arerepeated for a plurality of different audio instructions such thatexternal device displays graphic instructions that are synchronized withthe audio instructions generated by the defibrillator during theemergency use of the defibrillator.

In another method aspect, an interface unit attached to a basedefibrillator unit periodically receives status information from a basedefibrillator unit and transmits the received status information to oneor more remote servers. In some embodiments, such status checks arerepeated once each day. A wide variety of information may be transmittedas part of the status check. By way example, the status checks mayindicate one or more of: battery charge level; charging status;installed firmware version; date and time of latest firmwareinstallation; hardware version; serial number; a set of recent self-testresults; the base unit's functionality status and/or a variety of otherstatus information.

In another method aspect, the interface unit may receive incidentinformation from a base defibrillator unit during emergency use of thebase defibrillator unit. Some or all of the incident information may betransmitted to one or more remote servers for use by emergencyresponders and/or medical personnel. Some of the incident informationmay also be made available for display on the interface unit itself foruse as appropriate by responders or to provide graphic instructions to aresponder. By way of example, the incident information may include oneor more of: the base unit's operational state; an indication of acurrent instruction that the base defibrillator unit is currentlyissuing to a user; a timestamp indicating when the base defibrillatorunit went into emergency mode; an indicator indicating whether anydefibrillation shock(s) have been delivered, and if so, a timestampindicating the time at which each defibrillation shock was delivered; anenergy level delivered for each shock; a waveform associated with eachshock delivered; a shock/no shock classification for a detected ECGanalysis; a heart rhythm classifications for a detected ECG analysis; atimestamp or equivalent associated with a detected ECG analysis; one ormore recorded ECG samples; a report of any malfunctions that aredetected during an activation of the base defibrillator unit; and/or avariety of other incident information.

In yet another aspect, methods of managing power received by adefibrillator unit from one or more external devices that areelectrically connected to the defibrillator unit are described. In someembodiments, the defibrillator's battery may be opportunisticallycharged using power provided by a connected external device. In someembodiments, when it is determined that the defibrillator unit is in acapacitor charging state, power is drawn from the external device tocharge, or supplement the charging of, the capacitor unit. In variousembodiments, the connected external device may take the form of a mobilecommunication device, a supplemental battery pack mounted on andattached to the defibrillator; or an interface unit mounted on andattached to the defibrillator unit.

In some embodiments, a rechargeable battery on an interface unitattached to the defibrillator may be recharged when the defibrillatorunit is not in the capacitor charging state and it is determined thatthe defibrillator unit's rechargeable battery does not need recharging.

In another aspect, defibrillator support applications are described thatare suitable for use on the interface unit or on external devices suchas cellular phones or other mobile communication devices are. Thedefibrillator support applications may have programmed instructionsarranged to control the interface unit or other external devices toperform the functions and methods described herein.

DETAILED DESCRIPTION

The present disclosure relates generally to modular defibrillators.Referring initially to FIGS. 1A-1C, a modular defibrillator architecturein accordance with one embodiment will be described. The illustratedarchitecture is well suited for use in automated external defibrillators(including both semi-automated and fully automated defibrillators)although it may also be used in manual defibrillators and hybriddefibrillators that may be used in either automated or manual modes.

The core of the modular defibrillator system 100 is a basedefibrillation unit (base unit) 110. The base defibrillation unit 110 isa fully functional defibrillator that is configured so that itsfunctionality can be supplemented by connecting the base unit 110 to amobile communication device 105 (such as a smartphone, a tabletcomputer, etc.) having a defibrillator control app installed thereon, orby attaching an interface unit 200 to the base unit 110. In someembodiments, a charging pack 290 or other supplemental power storageunit can be attached to the base defibrillation unit to recharge abattery on the base unit, as appropriate, thereby effectively extendingthe base unit's usable life without an outside charge or batteryreplacement.

The interface unit 200 is ideal for enterprise applications as it mayhave wireless communication capabilities (e.g., Cellular, Wi-Fi,Bluetooth, etc.) and/or position sensing capabilities (e.g., GPS, GNSS,etc.) to improve both: (a) in-emergency patient care; and (b) unittracking, maintenance and updating. In some embodiments, the interfaceunit also has a display screen that can be used to display graphicsand/or videos that can assist in both emergency and maintenance &monitoring activities. For users that do not require an interface modulethat permanently connects to the base unit, the wireless connectivity,as well as graphical touch screen functionality, can be made availableby connecting a personal communication device such as a smartphone ortablet computer with a defibrillator app installed thereon to the baseunit. Both the interface unit and a connected personal device executinga defibrillator app can be configured to facilitate training, which cantake a wide variety of forms—as for example by: displaying trainingvideos; providing answers to frequently asked questions (FAQs);accessing external resources; and providing guidance through visual cuesduring an emergency, such as how to perform CPR or where to place theelectrode pads.

In FIG. 1A, the base unit 110, the mobile communication device 105 andthe interface unit 200 are shown separately to highlight those separatecomponents. In FIG. 1B, the interface unit 200 is shown attached to thebase unit 110 illustrating one particular use scenario in which theinterface unit is used as a supplemental interface for the basedefibrillator unit. In FIG. 1C, a mobile communication device 105 isshown attached to the base unit 110 illustrating a second use scenarioin which the mobile communication device 105 is utilized as asupplemental interface and power supply for the base defibrillator unit.

Base Unit

FIG. 2A is a perspective view of a representative base unit 110 andFIGS. 2B-2G are respectively top, front, back, bottom, right side andleft side views thereof. The base unit 110 is a fully functionaldefibrillator. As such, it includes all of the components andfunctionality required for defibrillation. This may include, forexample, all electronics required for defibrillation, a set of electrodepads, and a simple user interface for communicating instructions to auser and for receiving any necessary user inputs. As such, the base unitprovides all the components and functionality needed for instructing auser in how to operate the unit, analyzing a patient's heart rhythms todetermine whether they are experiencing a shockable cardiac rhythm, andif so, delivering a shock to a patient. The user interface, which mayinclude one or more user input buttons, a speaker for audioinstructions, and/or other components provides all of the functionalitynecessary for directing user actions and receiving necessary inputs fromthe user, during use of the base defibrillator unit—e.g., during acardiac treatment event. The base unit also includes a cartridge 117, orother suitable mechanism, that houses electrode pads 116 that attach toa patient.

Externally, the base unit housing 120 includes status indicator 175, apower-on (activation) button 183, a shock button 186 and one or moreexternally accessible electrical connectors. The shock button 186 can bedeactivated or eliminated if the defibrillator will only function in afully automated mode in which no user inputs are required to initiate adefibrillation shock. In the illustrated embodiment, the electricalconnectors include an interface connector 190 for electrically couplingthe base unit to an interface unit 200, and a mobile connector port 195(such as a USB, Micro USB, Lightening or other suitable connector) forelectrically coupling the base unit to a mobile communication device 105and/or other compatible devices. In other embodiments, additionalconnectors may be provided and/or one or more of the connectors 190, 195may be eliminated. For example multiple connector ports 195 may beprovided having the same or different form factors to facilitatecoupling different types of mobile communication devices. Similarly aconnector analogous to interface connector 190 may be provided on thebottom surface of the base unit housing 120 to facilitate electricallycoupling the base unit to an external charging pack 290 (e.g. batterypack) or to a charging dock. Therefore, it should be appreciated thatthe externally accessible user interface mechanisms and electricalconnectors can vary widely to meet the needs of any particularimplementation. In some embodiments, the base unit may optionallyinclude a wireless communication module 134, such as a Bluetoothcommunication module, to facilitate wireless communication with externaldevices. The base unit may also optionally include an inductive chargingreceptor 274 to facilitate receiving power from external deviceswirelessly.

In the top view of FIG. 2B, the power-on/activation button 183 is to theleft, and the shock button 186 is at right. The electrical contacts forinterface connector 190 are visible at center. Note how the buttons areclearly visible from this top view. There are speaker perforations inthe housing at both ends of the base unit so that audio instructionsfrom the base unit can be heard from any direction. In otherembodiments, the speaker(s) and any required perforations can bepositioned at other suitable locations—as for example on the top of thebase unit, at one end of the base unit, etc. In some embodiments, thespeaker perforations may be eliminated altogether.

In the illustrated embodiment, the electrode pads 116 are placed in anelectrode pad cartridge 117 as best seen in the front view of FIG. 2C.The cartridge 117 is replaceable and include a pull tab (removal tab)118 that is most visible in the top view of FIG. 2B. When a user pullsthe removal tab 118 the cartridge 117 opens to expose the electrode pads116. In other embodiments, pulling the removal tab draws the pads fromthe housing without the cartridge. Optionally, pulling the cartridgeopen, or simply pulling the removal tab, may cause and the electrode padpackaging to tear open revealing the electrode pads thereby eliminatingthe need for a user to open the pad packaging during an emergencycardiac incident.

The back view of FIG. 2D shows an externally accessible mobile connectorport 195 that takes the form of USB port. The connector port 195 canoptionally have a dust cover insert (not shown) that fits over the portwhen not in use and protect it from liquids and dust. The USB port isused to connect the base unit 110 with USB compatible power sources forrecharging the base unit and/or connecting the base unit with a personalcomputation device having a defibrillator App installed thereon. The Appprovides in-sync educational graphics to supplement the base unit'saudio instructions during an emergency, as well as providing diagnosticsand updates for the base unit. The App also facilitates the transfer ofbase unit status information to a remote management server. At right isstatus indicator 175 which includes icons and lights, used to inform auser of the functionality status of the base unit. The status indicatoris described in more detail below.

The edges of the housing 120 are generally tapered or rounded. However,the bottom has a flat edge to prevent rolling when placed on slantedsurfaces as best seen in the end views of FIGS. 2F and 2G. Speakerperforations 181 in the ends of the housing 120 are also best seen inthe end views of FIGS. 2F and 2G. In the right side view of FIG. 2F, theshock button 186 is visible at the top. The power-on/activation button183 is visible at the top of the right side view of FIG. 2G.

In the embodiment of FIGS. 2A-2G, the base unit includes a housing 120that houses the electrical components of the defibrillator. The specificelectrical components used by the base unit may vary widely so long asthe base unit can function as a fully functional, stand-alone device.

Although a USB port is shown, it should be appreciated that the mobileconnector port 195 can take any suitable form including currentlyexisting and later developed connector formats. By way of example, theconnector port may take the form of any type of USB connector (e.g.,including a USB-C connector; a USB 2.0 connector; a USB 3.0 connector; aUSB 3.1 connector; a USB mini connector; a micro USB connector, etc.) alightening connector or any other suitable connector format.

FIG. 3A is a block diagram illustrating one representative electronicscontrol architecture and associated components suitable for use in thebase defibrillator unit 110. In the illustrated embodiment, theelectronic components include a defibrillator controller 130, memory133, a charging power regulator 140, a voltage booster 145 (which mayhave multiple stages), a high voltage capacitor 150 for temporarilystoring sufficient electrical energy suitable to provide adefibrillation shock, discharge control circuitry 160, pad relatedsensing circuitry 162 and relays 169, power storage unit 170, batteryregulator 193, status indicator(s) 175, speaker(s) 180 and one or moreelectrical connectors (e.g., interface connector 190, mobile connectorport 195, charger connector 197, etc). The charging power regulator 143and voltage booster 145 which cooperate to control the charging of theshock discharge capacitor 150 are sometimes referred to herein as acharging circuit.

The defibrillator controller 130 is configured to control the operationof the base defibrillator unit and to direct communications withexternal devices, as appropriate. In some embodiments, the defibrillatorcontroller includes a processor arranged to execute software or firmwarehaving programmed instructions for controlling the operation of the baseunit, directing interactions with a user and communications withexternal components.

As will be described in more detail below with reference to FIGS. 3B and8, the base defibrillator unit 110 may optionally be configured so thatit is capable of drawing power from certain other available powersources beyond power storage unit 170 to expedite the charging of shockdischarge capacitor 150. The charging power regulator 140 is configuredto manage the current draws that supply the voltage booster, regardlessof where that power may originate from. For example, in someembodiments, supplemental power may be supplied from a mobile devicecoupled to mobile connector port 195 or from a portablecharger/supplemental battery pack coupled to charger connector 197.

The voltage booster 145 is arranged to boost the voltage from theoperational voltage of power storage unit 170 to the desired operationalvoltage of the discharge capacitor 150, which in the describedembodiment may be on the order of approximately 1400V-2000V (althoughthe defibrillator may be designed to attain any desired voltage). Insome embodiments, the boost is accomplished in a single stage, whereasin other embodiments, a multi stage boost converter is used. A fewrepresentative boost converters are described in the incorporated U.S.Pat. No. 10,029,109. By way of example, in some embodiments, a flybackconverter, as for example, a valley switching flyback converter may beused as the voltage booster 145—although it should be appreciated thatin other embodiments, a wide variety of other types of voltage boosterscan be used.

A voltage sensor 151 is provided to read the voltage of the capacitor150. The voltage sensor 151 may take the form of a voltage divider orany other suitable form. This capacitor voltage reading is utilized todetermine when the shock discharge capacitor 150 is charged suitably foruse. The sensed voltage is provided to controller 130 which determineswhen the capacitor 150 is charged sufficiently to deliver adefibrillation shock. The capacitor 150 can be charged to any desiredlevel. This can be useful because different defibrillation protocolsadvise different voltage and/or energy level shocks for differentconditions. Furthermore, if the initial shock is not sufficient torestart a normal cardiac rhythm, some recommended treatment protocolscall for the use of progressively higher energy impulses in subsequentlyadministered shocks (up to a point).

The discharge circuitry 160 may take a wide variety of different forms.In some embodiments, the discharge circuitry 160 includes an H-bridgealong with the drivers that drive the H-bridge switches. The drivers aredirected by defibrillator controller 130. The H-bridge outputs abiphasic (or other multi-phasic) shock to patient electrode pads 116through relays 169. The relays 169 are configured to switch between anECG detection mode in which the patient electrode pads 116 are coupledto the pad related sensing circuitry 162, and a shock delivery mode inwhich the patient electrode pads 116 are connected to H-Bridge tofacilitate delivery of a defibrillation shock to the patient. Althoughspecific components are described, it should be appreciated that theirrespective functionalities may be provided by a variety of othercircuits.

The pad related sensing circuitry 162 may include a variety of differentfunctions. By way of example, this may optionally include a padconnection sensor 164, ECG sensing/filtering circuitry 165 and impedancemeasurement filter 166. The pad connection sensor is arranged to detectthe pads are actually connected to (plugged into) the base defibrillatorunit 110. The ECG sensing/filtering circuitry 165 senses electricalactivity of the patient's heart when the pads are attached to a patient.The filtered signal is then passed to defibrillator controller 130 foranalysis to determine whether the detected cardiac rhythm indicates acondition that is a candidate to be treated by the administration of anelectrical shock (i.e., whether the rhythm is a shockable rhythm) andthe nature of the recommended shock. When a shockable rhythm isdetected, the controller 130 directs the user appropriately and controlsthe shock delivery by directing the H-bridge drivers appropriately.

In some embodiments, the power storage unit 170 takes the form of one ormore batteries such as rechargeable Lithium based batteries includingLithium-ion and other Lithium based chemistries, although other powerstorage devices such as one or more supercapacitors, ultracapacitors,etc. and/or other battery chemistries and/or combinations thereof may beused as deemed appropriate for any particular application. The powerstorage unit 170 is preferably rechargeable and may be recharged via anyof a variety of charging mechanism. In some embodiments, the powerstorage unit 170 takes the form of a rechargeable battery. Forconvenience and simplicity, in much of the description below, we referto the power storage unit 170 as a rechargeable battery. However, itshould be appreciated that other types of power storage devices canreadily be substituted for the battery. Also, the singular term“battery” is often used and it should be appreciated that the batterymay be a unit composed of a single battery or a plurality of individualbatteries and/or may comprise one or more other power storage componentsand/or combinations of different power storage units.

In some embodiments, the base defibrillator unit 110 is capable ofdrawing power from other available power sources for the purpose of oneor both of (a) expediting the charging of shock discharge capacitor 150and (b) recharging the power storage unit 170. In some embodiments, thebattery can be recharged using one or more of the externally accessibleconnector port 195, a dedicated charging station 294, a supplementalbattery pack (portable charger) 290, an interface unit 200, etc. as willbe described in more detail below. When wireless charging is supported,the base defibrillator unit may include a wireless charging module 174configured to facilitate inductive charging of the power storage unit170 (e.g. using an inductive charging station 294, or other devices thatsupport inductive charging, as for example an inductively chargingbattery pack, a cell phone with inductive charging capabilities, etc.).

As suggested above, a number of different types of devices may becoupled to the base defibrillator unit 110. Many of these devices can beused to supply power to the base unit 110 as illustrated in FIG. 3B.These can include a mobile device connected via connector port 195, acharger coupled via charger connector 197, a battery pack coupled viaconnector port 195 or charger connector 197, an inductive charger thatinductively provides power via inductive charging receptor 274, aninterface unit 200 coupled via interface connector 190 and/or othersuitable devices coupled through any of the described or otherappropriate connection mechanisms.

In the embodiment illustrated in FIG. 3B, power from any connecteddevice is made available to a battery charger/maintainer 173. Thebattery charger/maintainer 173 is configured to output power at a levelsuitable for charging battery 170. The voltage level of most batterieswill vary based on their charge levels, and for some batteries, such aslithium-based batteries it is desirable to vary the output voltage ofthe battery charger 173 based on the voltage level of the battery beingcharged. In such applications, the output voltage (v_(bc)) of thebattery charger 173 is adjusted to meet the needs of the battery. Theoutput of the battery charger is also made available to the chargingpower regulator 143 and to the other defibrillator electronics viabattery regulator 172. In the illustrated embodiment, the batteryregulator 172 may be arranged to adjust the voltage of power receivedfrom the battery (v_(b)) and/or the voltage of power received from thebattery charger (v_(bc)) to a level suitable for use by thedefibrillator controller 130 and the other defibrillator electronics(e.g. 3.3 volts).

If an auxiliary device is connected at the time of an emergency use ofthe defibrillator, and has power that is available for use during theemergency, such power can also be used to supplement power supplied tothe capacitor charging circuitry from the battery 170 during charging ofthe shock discharge capacitor 150. In the illustrated embodiment, thisis accomplished by making the output of battery charger 173 available tothe charging power regulator 143. In this way, if an auxiliary device isconnected and available to supply, the battery charger 173 can be turnedon to convey power from the connected device. The battery charger 173inherently outputs power at the appropriate voltage level (v_(bc)). Ifthe discharge capacitor charging circuit is turned on, the chargingpower regulator 143 will draw the power supplied by the battery charger173. When the discharge capacitor charging circuit is turned off, poweroutput from the battery charger 173 goes primarily to charge the battery170 (although some may be used to power the other defibrillatorelectronics as well). This is noteworthy because to the extent it isavailable, power may be drawn from a connected auxiliary devicethroughout the emergency incident for capacitor charging and/or batterycharging purposes as appropriate. This helps mitigate the risk that adefibrillator may be or become inoperable at the time of need, even if aparty that is responsible for maintaining the AED forgets to replace orrecharge the batteries when appropriate.

As a practical matter, the auxiliary device(s) most likely to beconnected during an emergency incident are expected to be a mobiledevice 105 connected to mobile connector port 195, a supplementalbattery pack 290 and/or an interface unit although other auxiliary powersources are possible. If more than one auxiliary device is coupled atthe time of an emergency, the defibrillator controller 130 and/or thebattery charger 173 may draw power from one or more of the connecteddevices in accordance with any desired power management scheme.

In some embodiments, the voltage booster 145 may be arranged to drawpower in short pulses (e.g. a flyback converter has short current drawperiods where current is drawn into the primary coil followed by short“off” periods where current is not drawn into the primary coil). In somesuch embodiments, the charging power regulator 143 is arranged to drawpower from the battery 170 (and when available the battery charger 173)in corresponding pulses to power the voltage booster. When power isavailable from a connected external device through battery charger 173,power drawn from the connected external device may be made available forpower defibrillator electronics and/or charging the battery 170 duringthose periodic voltage booster current draw “off” intervals.

In the power path described above, power from any connected auxiliarydevice(s) is made available to the charging power regulator 143 via thebattery charger 173. However, it should be appreciated that in otherembodiments, power from an auxiliary device may be made available to thecharging power regulator 143 via other suitable connection schemes.

One other connection path is also shown in FIG. 3B. Specifically, powerreceived through mobile connector port 195 may also be fed directly to adraw regulator 141 and from draw regulator 141 to the charging powerregulator 143, thereby bypassing the battery charger 173. This path isparticularly useful in the event that the battery 170 is fullydischarged and not able to supply power suitable for charging the shockdischarge capacitor 150. In some embodiments, this path is only used incircumstances in which power is not available from the battery. In suchembodiments, a switch (not shown) may be provided which opens the direct(charger bypass) connection path if the battery charge is below adesignated level. The charger bypass connection path is particularlydesirable when power is not available from the battery inimplementations in which the battery charger 173 steps-down the voltagelevel (v_(m)) of power received from the mobile connector port tofacilitate battery charging. The, the charger bypass eliminatesinefficiencies due to the voltage step down that occurs in the batterycharge 173 and the corresponding extra voltage step up required bycharging power regulator 143. These efficiencies are particularlyimportant in the event that power is not available from the battery andall of the charging power must be provided by a mobile (or othersuitable) device connected to connector port 195. In some embodiments,(as for example the embodiment illustrate in FIG. 3B), mobile connectorport 195 takes the form of a USB connector that conforms with USBprotocols—which frequently provide USB power (v_(m)) at approximately 5volts.

The mobile device draw current regulator 141 is configured to ensurethat the charging circuit does not draw more current than the mobilecommunication device can provide. This is important because manycellular phones and tablet computers have safety circuits that cut offthe delivery of electrical current if too much current is drawn at anytime. If the defibrillator unit 110 trips the safety circuit by drawingmore current than permitted by the attached device (e.g. phone), thedevice's (phone's) safety circuit will cut off power from being drawnfrom the I/O port and it may be some time before connector power isrestored—which is undesirable. At the same time, during charging of thedischarge capacitor(s) 150, it is desirable to draw very close to asmuch power as the phone has the ability to provide because the chargetime is inversely proportional to the drawn current. Therefore,restricting the charging current draw to a level noticeably below themaximum current that can be drawn from the phone will causeunnecessarily slow charging. Thus, a goal for the draw current regulator141 is to maintain the current drawn from the phone at a level that isvery close to, but is assured not to exceed, the maximum current that isknown to be obtainable from the phone. Preferably, current is drawnsubstantially continuously from the phone, rather than in periodicbursts dictated by the voltage boosting circuitry as is common in mosttransformers and other voltage boosting circuits.

By way of example, limiting the charging current to just under 500 mAhas been found to work well with most older smart phones includingphones ranging from various older Blackberries to Samsung Galaxy S5/S6.This is because many such phones utilize USB 2.0 or similar connectorsand the USB 2.0 specification calls for the delivery of 500 mA at 5V.Even these current draw rates facilitate charging the capacitor 150sufficiently to deliver a 150 joule defibrillation shock within anappropriate period based on the expected set-up time for defibrillationfor the first shock and the recommended interval between shocks for anysubsequent shocks that may be advised (defibrillation shocks aretypically recommended every two minutes if necessary duringresuscitation). Most newer phones support significantly higher currentdraw rates which facilitate even faster charging. By way of example,phones utilizing USB 3.0 connectors are typically able to continuouslydeliver 900 mA at 5V and many modern phones support significantly highercurrent draws.

The draw current regulator 141 may take a variety of forms. Although notrequired in all embodiments, in some embodiments, the draw currentregulator is configured to (1) maintain the input current at a generallystable level that is close to, but never exceeds the maximum currentthat can be delivered by the phone, and (2) keep parasitic power losseslow. In some embodiments, the current level drawn by draw currentregulator 141 can be set dynamically at the time of use based on thecurrent delivery capabilities of the connected device or otherappropriate factors. In some embodiments, a digitally controlled currentregulator may be used as the draw current regulator 141. By way ofexample, a digitally controlled current limiting Buck converter that iswell suited for use as the draw current regulator 141 is described inU.S. Pat. No. 10,029,109) which is incorporated herein by reference. Aparticularly desirable characteristic of that type of current regulatoris that is current is continuously drawn from the power supply (e.g. themobile device battery) during the discharge capacitor charging process.This contrasts with traditional defibrillator designs in which the powerto charge a discharge capacitor is drawn from the power supply inperiodic intervals. Additionally, the current is drawn from the powersupply at a relatively constant rate even as the capacitor chargeincreases, which again is quite different than conventional designs.

Once the shock discharge capacitor 150 is charged to the desired level,power received through the connector port 195 may be directed to thebattery charger 173 to facilitate charging the battery unless or untilpower is again needed to charge (recharge) the shock discharge capacitor150.

The base unit also includes a number of software or firmware controlalgorithms installed in memory 133 and executable on the defibrillatorcontroller. The control algorithms have programmed instructions suitablefor controlling operation of the base unit and for coordinatingcommunications between the base unit 110 and the interface unit 200,connected devices 105, and/or any other attached or connected devices.These control routines include (but are not limited to): heart rhythmclassification algorithms suitable for identifying shockable rhythms;capacitor charge management algorithms for managing the charging of thedischarge capacitor; capacitor discharge management algorithms formanaging the delivery of a shock as necessary; user interface managementalgorithms for managing the user instructions given by the defibrillatorand/or any connected user interface devices (e.g. interface unit 200,mobile communication device 105) during an emergency; battery chargecontrol algorithms for managing the charging of power storage unit 170and routing charging power to other connected components (e.g.,interface unit 200 or supplemental battery pack 290); testing andreporting algorithms for managing and reporting self-testing of the baseunit; software update control algorithms and verification files thatfacilitate software updates and the verification of the same.

Interface Unit

The interface unit 200 is preferably designed so that it may besecurely, but removeably, attached to the base defibrillation unit 110.The interface unit 200 is configured to both: (a) facilitateinteractions with a user during an emergency use and to furtherfacilitate patient care during an emergency; and (b) facilitatenon-emergency monitoring and/or use of the device such as training, unittracking, maintenance and reporting functionalities. In the primarydescribed embodiments, the interface unit includes a digital screen toprovide graphic instructions synced with the audio instructions providedby the base unit during use. The interface unit also providesconnectivity and GPS location which allows for remote monitoring andmaintenance of the connected base unit. The interface unit is configuredto facilitate automated EMS contact during an emergency and uploadsimportant incident related data such as cardiac arrest ECG samples. Theinterface unit can also serve as a conduit for remote software updatesfor the base unit to facilitate both device improvement and productfixes. Thus, the interface unit is ideal for commercial users whorequire remote monitoring and maintenance. In other embodiments, theinterface unit may have just the display screen and not the connectivityelements, or just the connectivity elements and/or GPS functionalitywithout a display screen or any other desired combination offunctionalities.

A variety of attachment mechanisms can be used to facilitate attachingthe interface unit 200 to the base unit as will be described in moredetail below with reference to FIGS. 5A-5E. In some implementations, theinterface unit 200 includes an interface housing 202 that attaches tothe base unit via a press fit or an elastic form fit. Preferably all ofthe user interface features on the base unit 110 remain functional andusable when the interface unit 200 is attached thereto.

FIG. 4 illustrates some of the electrical components of a representativeinterface unit 200. In the illustrated embodiment, the interface unit200 includes an interface controller (processor) 210, memory 213, adisplay screen 220, a communications module 230, an electrical connector240, an interface unit power storage unit 250, and a location sensingmodule 260, all of which may be housed within the interface unit housing202. The interface unit may also have software or firmware (such as anapp 270) installed or installable in memory 213 having programmedinstructions suitable for controlling operation of the interface unitand for coordinating communications between the interface unit 200 andthe base defibrillation unit 110 and/or remote devices.

The processor 210 controls operation of the interface unit andcoordinates communications with both the base unit 110 and remotedevices such as a central server (as will be described in more detailbelow). In some embodiments, the processor 210 is arranged to execute adefibrillator app 270 that can be used both during use of thedefibrillator system 100 during a cardiac arrest incident and tofacilitate non-emergency monitoring or/or use of the defibrillatorsystem 100.

The display screen 220 is suitable for displaying text, graphics and/orvideo under the direction of the processor 210 to assist both duringboth emergency situations and at other times. In some embodimentsdisplay screen 220 is touch sensitive screen suitable for receivinginputs based on a graphical user interface displayed thereon. In someembodiments an optional graphics controller 222 may be provided tofacilitate communications between the interface control processor 210and the display screen 220.

The communication module 230 is provided to facilitate communicationswith remotely located devices such as the central server. Thecommunications module 230 may be configured to utilize any suitablecommunications technology or combination of communication technologiesincluding one or more of cellular communications, Wi-Fi, satellitecommunications, Bluetooth, NFC (Near Field Communications), Zigbeecommunications, DSRC (Dedicated Short Range Communications) or any othernow existing or later developed communications channels using anysuitable communication protocol. By way of example, in the illustratedembodiment, the communications module 230 includes Wi-Fi, cellular andBluetooth modules 231, 232 and 232 that facilitate Wi-Fi, cellular andBluetooth communications respectively.

The electrical connector 240 is configured to mate with interfaceconnector 190 on the base defibrillator unit 110. The connectors 190 and240 are configured to facilitate communications between thedefibrillator controller 130 and the interface unit's processor 210. Theconnectors 190 and 240 are also preferably arranged to supply power fromthe interface unit 200 to the base unit 110 as will be described in moredetail below. In some embodiments, power will only be provided in onedirection—i.e., from the interface unit 200 to the base unit 110 and notin the reverse direction during operation. A good reason for thisapproach is that the defibrillator is the most important component froma safety standpoint and it is often undesirable to draw power from thebase unit to power other devices (including the interface unit 200) in amanner that could reduce the energy available to charge the dischargecapacitor in the event of an emergency. However, in some embodiments,the power supply may be bi-directional (at least in some circumstance)if desired—as for example if the base unit is not in use, is fullycharged and plugged into an external charging power supply, etc.; or ifthe power passed to the interface unit is not coming from the baseunit's internal battery (e.g., it is coming from a charger, a mobilecommunication device, or other device connected or attached to the baseunit), etc.

The connectors 190 and 240 can take a variety of forms. They can beconnectors with accompanying transceivers configured to handle processorlevel communications (such as UART, SPI, or I2C transceivers), withadditional pins for power delivery (Power+GND), and connectionverification (i.e. a pin that detects when there is a connection betweenthe interface unit and the Base AED and triggers an interrupt on theBase AED signifying that there is not a unit connected). They can alsobe more standardized connectors such as USB connectors.

The interface power storage unit 250 provides power to operate theinterface unit 210. In many embodiments, the power storage unit takesthe form of a battery 252 with associated control components, althoughagain a variety of other power storage technologies such assupercapacitors, ultracapacitors, etc. may be used in other embodiments.The associated control components may include components such as abattery charger and maintainer 254, which may include various safetymonitors, and battery regulator 256. Preferably, the power storage unit250 is rechargeable, although that is not a requirement. In someembodiments it may be desirable to utilize replaceable batteries(rechargeable or not) so that the batteries in the power storage unit250 can be replaced when they near the end of their useful life. In someembodiments, the power storage unit 250 may also be arranged to supplysupplemental power to the base unit 110. Depending on the structureand/or state of the base unit, the supplemental power can be used tohelp charge the discharge capacitor 150 during use; to power or providesupplemental power for the defibrillator electronics and/or to chargethe base defibrillator unit's power storage unit 170. In otherembodiments, a supplemental battery within the interface unit (notshown) may be used to provide the supplemental power for the base unitrather than the power storage unit 250.

The interface unit may also optionally include various environmentalsensors 263 and other peripheral components 266. When desired, theinterface unit may include any of a wide variety of different types ofsensors and peripheral components. For example, in selected embodiments,the interface unit may include one or more accelerometers and/orgyroscopes, a temperature sensor, a humidity sensor, a time of day orany other desired sensors or components.

The interface unit 200 is preferably configured to securely mechanicallyattach to the base unit 110. Typically, the interface unit is detachablesuch that it may be separated from the base unit if desired—although inother embodiments, the attachment may be more permanent in nature. Thespecific mechanical attachment utilized may vary widely in accordancewith the needs of any particular embodiment. In some embodiments, pressor form fitting attachment structures are used, while in others, latchand catch mechanisms, snap fit structures, etc. are utilized alone or incombination to releasably attach the interface unit to the base.However, it should be appreciated that a wide variety of otherstructures can be used in other embodiments. A few specific mechanicalattachment structures are described below.

In some embodiments, the interface unit includes an attachment sensor(not shown) that senses when the interface unit is attached to a baseunit.

The base unit 110 can also be coupled to a mobile communication device105 such as a cell phone, a tablet computer, a personal digitalassistant (PDA) or other portable computing device as seen in FIG. 1C.In the embodiment illustrated in FIG. 1C, the mobile communicationdevice takes the form of a smartphone such as a Samsung Galaxy or anApple iPhone. However, in other embodiments, a wide variety of othercell phones or other mobile communication devices may be used in placeof the smartphone. The mobile communication device 105 is coupled to thebase defibrillation unit 110 via a connector cable 113 that plugs intothe connector port 195. In other embodiments, the connector port 195 canbe replaced by a connector cable that is permanently hard wired to thedefibrillation unit. In still other embodiments, the mobilecommunication device can couple wirelessly with the base unit.

A defibrillator app 270 can be installed on the mobile communicationdevice 105 to provide much or all of the defibrillator interface,control, monitoring and reporting functionality available to thedefibrillator. The mobile communication device 105 can also providepower to the base defibrillation unit 110. In some preferredembodiments, power drawn from the mobile communication device issufficient to power all of the base unit's electronics, includingcharging the discharge capacitor to a level suitable for shock deliveryin a timely manner to facilitate use of the base unit even in thecircumstance that the base unit's power storage unit 170 is completelydrained and no other power is available to the base unit. That is, ifnecessary, the base unit 110 can be operated in a mode analogous to thearrangement described in Applicant's patent Ser. No. 10/029,109 which isincorporated herein by reference.

As suggested above, the attachment of the interface unit 200 or theconnection of a personal phone or other mobile communication device 105that has a defibrillator app installed thereon supplements thefunctionality of the base unit in a number of ways. For example, duringemergency use, the system can automatically call 9-1-1, report thelocation of the victim and open a line of communication betweenEmergency Medical Services (EMS) and lay on-scene users. This fitsnicely with the U.S. federal initiative to expand emergencycommunications to include wireless and voice-over-IP devices(Next-Generation 9-1-1), text and video messaging, and geolocation.

Further, critical incident related information such as the time sincefirst shock, type of arrhythmia detected, number of shocks delivered,etc., can be relayed to responding EMS personnel en route, as well asdisplayed on the interface unit or personal phone screen once theemergency personnel arrive. Such real-time communication speeds patienttransitions between responders and decreases communication errors,ultimately improving patient outcomes.

Base units connected to the interface unit or a smartphone with adefibrillator app will benefit from the multitude of available sensorsto record information such as time, location, temperature, and humiditywhich can be used to infer SCA risk factors. Leveraging sensor dataavailable when defibrillators are used, we can begin to establish SCApatterns in low-risk individuals (e.g., mornings vs. evenings; high vs.lower temperature/humidity, etc).

Outside of an emergency, the described system can automate themaintenance process. For entities with several AED units, the GPSlocation of each unit, expiration dates, battery level, versions, etc.can all be accessed on a backend management platform, as described, forexample in Applicant's Provisional Patent Application Nos. 62/617,400and 62/652,193, each of which is incorporated herein by reference. Forall users, any critical notifications, including battery low, deviceexpirations, and system self-test failure indicating a problem with theAED unit, can be automatically sent via email and SMS to the appropriatepersonnel. Instead of AED fleet managers needing to manually inspecteach AED monthly, the information is available at their fingertips. Thiscan go a long way in addressing the current issue of ensuring AEDs areproperly maintained.

The attachment of an interface unit 200 or the connection of a mobilecommunication device 105 to the base unit also provides a mechanism forfacilitating software updates to the base unit itself. Specifically,secure software updates can be received by the interface unit or mobilecommunication and then transferred to and installed on the base unit110. This type of remote software updates allow for device performanceimprovements, as well as critical fixes for any bugs that arise withoutneeding to physically retrieve each unit. The ability to update anyencountered bug helps ensure that the AED is ready to go when needed.

In some embodiments, the interface unit has no substantial functionother than to operate in conjunction with the defibrillator but is notrequired for the defibrillator to operate properly. Indeed, in someembodiments, the interface unit cannot function when it is not connectedto a defibrillator.

In some embodiments, the interface unit 200 may utilize a smartpnone orotner mobile computing device as it functional core. This works wellbecause most smartphones today (including low cost smartphones)includemost all of the electrical components and processing power that are usedin or desired for use in the interface unit 200, all packaged into asmall package footprint. For example, most smartphones havesignificantly more processing power than required by the interface unit.They have a high quality touch screen displays that can be leveraged toguide a lay or minimally trained operator through an incident. They alsoprovide a user interface that potential users are very familiar with,which may reduce a lay user's reluctance to try to operate a life savingmedical device that they are not particularly familiar with in anemergency situation. They include integrated batteries that provide morethan enough power to power a defibrillator. They have built incommunication technologies such as cellular,

Wi-Fi and Bluetooth capabilities that can be used to facilitate avariety of response related services. They have built in GNSS systemsthat can be used to provide location information. They also have builtin sensors such as audio microphones, cameras, etc. that can be use inadvantageous ways during a medical incident.

Attachment of Interface Unit to Base Unit

As discussed above, the interface unit 200 is preferably designed sothat it may be securely, but removeably, attached to the basedefibrillation unit 110. A variety of attachment mechanism can be usedto facilitate such attachment. Preferably all of the user interfacefeatures on the base unit 110 remain functional and usable when theinterface unit 200 is attached thereto.

In some embodiments, screws or other suitable fasteners may be used toattach the interface unit to the base unit. Such an approach can behelpful in ensuring that the interface unit always lines up properlywith the base unit. In other embodiment, the interface unit can utilizean elastic form fit, a snap fit or an interference fit, to reduce thenumber of parts associated and complexity of the attachment. In stillother embodiments, the interface unit can include a latching mechanism.The latch mechanism may permit a user to latch the interface unit in toits proper placement on the base unit, but require a pull, push, lateralmovement, or other action by the user to remove the interface unit fromthe base unit. Regardless of the attachment style, the base unit andinterface unit can use surface contacts, spring pins, male-femaleadapters, or NFC or other wireless communications or other suitablemechanisms to connect electrically. One particularly desirable featureis that any mechanical attachment always lines up the electricalattachment between the two. In one embodiment, the base unit has surfacecontacts on it and the interface unit has compressible spring pins thatline up with the surface contacts on the base unit in order to form anelectrical connection. These electrical lines can include data lines forcommunication (e.g. receive/transmit data lines), a power line, a groundline, and a connection line. The connection line is provided to allowthe control systems to recognize that the interface unit is attached tothe base unit. Typically, the connection line completes an electricalcircuit that can be sensed by a control system to signify the presenceof a connected device.

In some implementations, a press fit or an elastic form fit is used tofacilitate the attachment of the interface unit to the base unit. FIG.5A is a perspective view of an interface unit in accordance with onesuch embodiment. FIGS. 5B-5E respectively, are top, front, side andbottom views of the interface unit of FIG. 5A. FIG. 5F is a crosssectional view highlighting how the interface unit matches the contoursof the base unit to provide a secure form fitting attachment to the baseunit.

In the embodiment shown in FIGS. 5A-5E, the interface unit includes ahousing 202 having four arms 204 that are designed to wrap around sideedges of the base unit to securely hold the interface unit 200 in place.The arms 204 have some elasticity so that they can flex to slide overthe base unit 110 when the interface unit is attached thereto, but haveenough stiffness so that they press against the base housing 120 firmlyhold the interface unit in place even during rough or awkward handlingof the combined unit and/or if the combined unit is dropped.

In some embodiments, the interface housing 202 is formed from arelatively stiff rubber-like material which provides the desiredflexibility for the arms. To secure the interface unit 200 to the baseunit 110, the interface unit may be pressed onto the base unit. As theinterface unit presses onto the base unit, and the arms 204 deform tothereby slide over the base unit. The distal ends of arms 204 aredesigned to wrap around the corners of the base unit 110 when attached,thereby securing the interface unit to the base unit.

In some preferred embodiments, the inner surfaces of arms 204 as well asother surface portions of the interface unit that face the base unit,match the contours of the base unit to help provide a snug fit betweenthe two devices. In the illustrated embodiment, the side edges of theinterface unit are somewhat rounded or tapered as best seen in FIG. 5F(convexly) and the form fitting arms 204 have matching contours (concaveon their internal surface). Thus, the arms 204 effectively grip the baseunit.

Since a press fit or an elastic form fit is used, the interface unit canbe removed from the base unit if desired. However, the interface unitwill stay in place once it is attached to the base defibrillation unitabsent an affirmative effort to detach the two units. In general, it isnot contemplated that the interface unit will be separated from the baseunit after it has been attached thereto except in relatively rarecircumstances. As such, the interface unit is typically not designed tobe taken on and off the base unit regularly and the form fit may bearranged such that the interface unit is not too easily removed after itis installed on the base unit. Although a particular form fittingstructure is illustrated, it should be appreciated that in otherembodiments, the interface housing 202 may utilize a wide variety ofother geometries.

As best seen in FIG. 1B, in the illustrated embodiment, the arms 204 areconfigured so that they do not cover power-on button 183, shock button186, mobile connector port 195, status indicator 175 or speaker 180 suchthat each of these components is readily accessible to users even whenthe interface unit 200 is in place. Thus, the base unit 110 may be usedin the same way regardless of whether the interface unit 200 is attachedthereto. The ability to use the base defibrillator in the same way,regardless of whether the interface unit is attached, providessignificant safety advantages. In some jurisdictions, this ability maybe beneficial from a regulatory standpoint as well. Specifically, whilethe base unit 110 may be subject to rigorous regulatory review, if theinterface unit does not impact the core functionality of the base unitand a potential failure of the interface unit would not impact theoperability of the base unit, the interface unit itself may be subjectto far less regulation. This can greatly reduce the expenses associatedwith regulatory review of the modular defibrillator since the basedefibrillator unit and the base unit/interface unit combination may notneed to be subject to separate full scale approval processes. The sameis true of the supplemental battery pack (portable charger) 290, whichalso, when attached (with or without the interface unit), does notinterfere with any of the functionality of the base unit 110.

Electrical connector 240, which electrically couples the interface unitto the base unit's interface connector 190 is exposed on the bottom ofthe interface unit, as can best be seen in FIG. 5E.

FIG. 6 is a perspective view of an alternative interface unit housing202(a) having another arm based securing arrangement. In thisembodiment, a reinforcing bar 205 is provided on each end of theinterface unit to connect the distal ends of the associated housing arms204(a). These reinforcing bars further increase the stability of theattachment to the base unit without interfering with the functionalityof any of the UI components of the base unit.

The reinforcing bars 205 increase the stiffness of the arms and thuscreate a more stable attachment of the interface unit onto a base unit.The reinforcing bars also provide more contact between the interfaceunit and the base unit, thereby further increasing stability of theattachment. In this embodiment, the reinforcing bars are only providedon the ends of the interface unit. When the interface unit is attachedto the base unit, the large spacing 206 between the legs engaging thefront and back surfaces of the base unit provide easy user access to theelectrode pads cartridge 117, the connector plug 195, and the statusindicators 175. The opening spaces 207 formed by the reinforcing bars205 provide access for the base unit buttons 183, 186 and the speakerperforations when the interface unit is attached to the base unit. Theconnector 240 for electrically connecting the interface unit to the baseunit is present on the bottom of the interface unit.

In other embodiments reinforcing bars could also be provided along thesides (not shown).

In the embodiments described with reference to FIGS. 5 and 6, theelasticity of the interface unit housing 202 provides the forcesnecessary firmly hold the interface unit in place without the use of anylatching mechanisms. However, it should be appreciated that in otherembodiments, the interface unit and/or the base unit may have otherstructures, as for example, complementary latch and catch mechanism (notshown) that further solidify the connection. For example, in oneparticular embodiment, the arms may have tabs at their distal tips thatfit into complimentary recesses on the bottom surface (or elsewhere on)the base unit.

When the interface unit 200 is attached to the base unit 110, electricalconnections are also made between the two units. In the illustratedembodiment, this is accomplished through connector 190 on the base unitwhich is engaged by a complimentary connector 240 on the interface unit200. The specific form of mating connectors 190 and 240 may vary widelyso long as they provide a solid electrical connection between thecomponents. In general, the connectors preferably support both powerdelivery and communications between the devices.

In one particular embodiment, the base unit connector 190 has aplurality of surface contacts 191 that are engaged by complimentaryresilient pins 241 on the interface unit connector 240. Representativesurface contacts on base unit 110 can be seen in FIG. 2B which is a topview of the base unit. A representative matching connector 240 withresilient pins 241 can be seen in FIG. 5E which is a bottom view of theinterface unit of FIG. 5A. The specific number of contact/pin pairs thatare provided may vary with the needs of any particular implementation.By way of example, in some embodiments, 5 contact/pin pairs are providedwith two contact/pin pairs being data receive and data transmit lines, athird pair conveying power, a fourth pair connecting ground, and a fifthpair being configured to confirm the connection. As will be familiar tothose skilled in the art, this is the type of interface structure usedis selected USB connectors and thus, USB logic may be used in suchembodiments. Indeed, in some embodiments, the mating connectors 190 and240 may take the form of USB connectors. However, in other embodimentthe data transmit and receive lines may use other protocols such asUART, SPI or I2C as previously mentioned. In still other embodiments,the power and ground pins, and/or the sense pin may be eliminated.

In other embodiments, near-field communications (NFC) or other wirelessprotocols may be used to electrically couple the units. Of course a widevariety of other connector arrangements and pin assignments may beutilized in other embodiments. When male/female connectors are utilized,it is preferred (but not necessary) for the female connector to be onthe base unit so that it is less likely to be damaged by mishandling.

Battery Pack and Charging Stations

Another module that can be provided for use with the base unit is asupplemental battery pack 290—which might also be considered a portablecharger since it may be used to recharge the base unit's power storageunit 170. Like the interface unit, the supplemental battery pack 290 canbe attached to the base unit in a wide variety of different manners.

In some embodiments, the supplemental battery pack 290 is attached andelectrically connected to the base unit by securing it to the base unitin a manner that is substantially the same as described above for theinterface unit. In this embodiment, the supplemental battery packattaches in the same location as the interface unit, using the sameelectrical contacts, and the same connection mechanism. Optionally, aninterface unit 200 can then be secured to the supplemental battery packin the same manner while making the same type of electrical connectionsbetween the units. Such an arrangement is diagrammatically illustratedin FIG. 7A. With this approach, a stacked system is provided with theinterface unit 200 on the top, the supplemental battery pack 290 in themiddle and the base defibrillator unit 110 on the bottom as can be seenin the exploded view of FIG. 7A. When this approached is used, thesupplemental battery pack may utilize a connector format identical tothe interface unit's connector 240 on its lower surface to electricallyconnect to the base unit. The supplemental battery pack may also includea second connector on its upper surface that matches the configurationof base unit connector 190 to electrically connect the interface unit tothe battery pack and ultimately connect the interface unit to the baseunit when the interface unit is stacked thereon.

In other embodiments, the supplemental battery pack may be attached tothe bottom of the base defibrillator unit on the opposite side of thebase unit as the interface unit as illustrated in FIG. 7B. With thisarrangement, the base defibrillator unit rests on the supplementalbattery pack. When an interface unit is also attached in a stackedmanner, the interface unit 200 is on top, the base unit 110 in themiddle and the battery pack 290 on the bottom.

The bottom mounted supplemental battery pack may be attached to the baseunit using a variety of different mechanism. In some embodiments, thesupplemental battery pack is attached using an elastic form fittingapproach similar to that described above with respect to the interfaceunit. One such arrangement is shown in FIG. 7B. In the arms or otherattachment structures utilized on the supplemental battery pack arearranged so that they don't interfere with the arms 204 when theinterface unit is attached, or interfere with any of the base unit'sexposed user interface components or the connector 195.

It should be appreciated that these types of stacking architectures canbe continued to accommodate other modules as well. The various modulescan have defined orders in which they stack, or they may be universal inthe ability to stack any number of modules on top of one another, in anyparticular order. The modules can all use the same attachmentarchitecture, or different modules can use different attachments.

In some embodiment, the supplemental battery pack has a clip structure(not shown) so that the battery pack may be clipped onto the base unit110. Such a clip structure can also be used in association with a cradleon a wall or surface mounted charging station/dock to facilitatecharging the base unit. In some embodiments, the charging station mayserve as a dock in which the base unit may be stored with the chargerbeing used to charge the base unit in a manner appropriate formaintaining a long battery life. When a charging station is provided, itpreferably is arranged to receive the base unit in a manner in which theinterface unit, if present (or the top of the base unit if no interfaceunit is present) is exposed so that the interface unit is visible andaccessible.

In some embodiments, a dedicated “home dock”, mount, or cradle may beprovided for storing the defibrillator. Such a dock can be wall mounted,surface mounted or arranged in any other suitable configuration. Thedock may also serve as a charging station 294. The charging may beeither wireless (e.g. inductive) or via a connector. In embodiments thatfacilitate inductive charging, the base unit includes an inductivecharging receptor 274 that is used in conjunction with inductivecharging stations. In some embodiments, the dock/charging station mayalso be configured to communicate data through the inductive charger—asfor example, using NFC protocols.

FIG. 7C is an exploded perspective view of a representative inductivecharging station/dock 294 suitable for storing and charging the basedefibrillator unit. The charging station 294 includes a cradle 296suitable for holding the base unit 110 and any other modules attachedthereto. In some embodiments, the cradle may have a support structureform factor substantially similar to the form factor of a bottom mountedbattery pack 290. The charging station/dock may have a cord/plug toconnect with a wall outlet or it may have a large internal battery,which may be particularly desirable for units used off of the grid. Insome embodiments the dock can include connectivity features (e.g., WiFi,cellular, etc.) to facilitate monitoring the defibrillator while it isplaced in the dock, and to know when the AED is removed from its dock.In some embodiments, the dock may be configured to sound an alarm orsend a notification if/when the defibrillator is removed from the dock.Such notifications can be to emergency personnel, an administratorresponsible for the AED (e.g. a school administrator, a buildingmanager, etc.). In some embodiments particularly suitable for public usedefibrillators, the dock may also include a camera and/or microphone inthe home dock so law enforcement/EMS could see if someone is justplaying with the device or actually using in an emergency.

FIG. 7D is an exploded perspective view of an alternative chargingstation/dock 294(a). This embodiments includes an electrical connector297 configured to engage a bottom electrical connector on the base unitto facilitate charging the base unit. In this embodiment the cradle296(a) has arms 298 that are designed so that they do not overlap thearms 204 of the interface unit. This is sometimes helpful to ensure thatbase units having an interface unit 200 mounted thereon fit well in thecradle. However, it should be appreciated that cradle 296 of FIG. 7C canreadily be configured to hold defibrillators that include an interfaceunit as well.

In some embodiments, the supplemental battery pack 290 has an upperconnector that matches the electrical connector (e.g. 297) used in thecharging station. In this way, the base unit can be recharged throughthe use of either the supplemental battery pack or a dock/chargingstation that has electrical power. The supplemental battery pack mayalso optionally have a lower connector that mates with the chargingstation's electrical connector. This facilitates charging defibrillatorsthat include a battery pack without having to remove the battery pack.

Battery Life and Power Management

Battery life is a significant limitation for most battery powered AEDs.Typically, a conventional battery powered AED will be unusable when itsbattery is drained. Further, inspired by regulatory or other concerns,some manufacturers will disable their AEDs if/when the batteries exceedtheir designated shelf life even if the defibrillator would otherwise becapable of operating. Thus, in practice, fully discharged or otherwiseunusable batteries is a common failure mode for current AEDs. To give anexample of the scale of the problem, some studies have suggested that25% to 33% of all AED failures are attributed to the battery beingdischarged. Thus, it should be apparent that battery limitations are asignificant issue for existing AEDs.

The described modular defibrillator design attempts to mitigate thosepractical limitations in a number of ways. Initially, in many preferredembodiments, the power storage unit 170 (e.g. a battery/battery unit) isrechargeable so that the defibrillator can be recharged as necessary.The power storage unit 170 can be charged and recharged in a variety ofways.

In some embodiments, the base unit 110 includes an optional inductivecharging module 174 having an inductive charging receptor configured toreceive power from an inductive charger to charge the battery. Thisconfiguration is particularly useful in applications where it ispractical to store the AED on a dock that has power and doubles as aninductive charger. The defibrillator controller 130 has chargemanagement algorithms that manage the charging of the battery in amanner that prolongs battery life (regardless of where the chargingenergy comes from).

The base unit 110 can also be charged through connector 195—which maytake the form of a USB connector or other standard connector thatsupports the delivery of power. When a USB connector is utilized, thedefibrillator can be charged by plugging the unit into any USBcompatible device that can supply power over the USB connector. In somecircumstances, the connected device may be a mobile communication device105 such as a smartphone or a tablet computer and power for rechargingthe battery may be supplied by the phone or tablet. An advantage ofusing a mobile communication device is that such devices can alsoreadily be used as a supplemental user interface and to facilitate avariety of communications, monitoring, maintenance and trainingfunctions. However, it should be appreciated that there are a widevariety of other existing USB compatible devices that can be used torecharge the battery 170. These can include portable power sticks orpower banks; portable chargers; laptop computers; wall plug chargers;cigarette lighter chargers; and a wide variety of other devices.

The useful battery charge life of the base defibrillator unit (with orwithout a rechargeable battery) can be greatly expanded by attaching asupplemental battery pack 290 to the base defibrillator unit 110. Use ofthe battery pack 290 is particularly desirable in situations where thebase defibrillator unit is expected to be stored in a location separatefrom a charging station and/or the owner is not confident that thedefibrillator will be checked and charged on a regular basis and/orotherwise maintained as often as it should be if the unit doesn't havethe supplemental battery pack attached. In some embodiments, the batterypack 290 is used to recharge the base unit's power storage unit 170.Thus, the supplemental battery pack may be considered or take the formof a portable charging unit.

Still further, the useful battery charge life can be extended throughthe attachment of an interface unit 200—which has a power storage unit250 that can also be used to charge the defibrillator battery 170 asnecessary.

In some embodiments, the defibrillator base unit 110 further includes abattery charging/maintaining controller that manages the charging andmaintenance of the base unit battery 170 in a manner designed to prolongthe battery's useful life through multiple charging cycles. The batterycharging/maintaining controller may be part of the power storage unit170, a separate component, or it may be implemented algorithmically insoftware that executes on the defibrillator controller 130 so that thedefibrillator controller itself manages the charging of the powerstorage unit.

It should be apparent from the foregoing that power for recharging thebatteries used in the base defibrillator unit can come from a variety ofmodules/components that might be used in conjunction with the base unit.Similarly, a variety of different modules/components can be used tofacilitate monitoring and maintenance type communications between thebase unit and a remote server. Some of the possible power and datacommunication paths are diagrammatically illustrated in FIG. 10.

In the embodiment illustrated in FIG. 10, the base unit 110 includesinterface connector 190, a USB port that serves as connector port 195,an interface 199 that facilitates short range communications (e.g.Bluetooth, NFC, etc.) and a wireless charging receiver 174. Althoughthese four specific electrical connection mechanisms are shown in theembodiment of FIG. 10, it should be appreciated that various otherconnection mechanism may be used in other embodiments, and/or some ofthe illustrated connection mechanisms can be eliminated or substitutedfor. In the illustrated embodiment, either an interface unit 200 or aportable charger (supplemental battery pack) 290 may be attached to thebase unit and electrically coupled thereto by way of interface connector190. When present, the interface unit facilitates data communicationwith both the base unit 110 and with one or more remote servers 280,which in turn may facilitate communications with various emergency andmedical resources, as appropriate. Power may be provided to the baseunit through interface connector 190 from either interface unit 200 orportable charger 290. When appropriate, power originating from anexternal source may be supplied to the interface unit via base unit 110and interface connector 190 as well.

A mobile communication device 105 or other USB power source may beeclectically coupled to the base unit through connector port 195. Whenpresent, the mobile communication device 105 facilitates datacommunication with both the base unit 110 and with the remote server(s)280. Power may be provided to the base unit through connector 195 fromeither mobile communication device 105 or any other USB power source.

Wireless charging receiver 174 can facilitate the reception of inductivecharging power from home dock 294(b) or any other suitable wirelesscharging station 294(c). In some embodiments, the home dock 294(c) alsofacilitates communications with the base unit 110 through short rangecommunications interface 199, and may be arranged to communicate withremote server 280 as well.

Battery Charge Management

There are a variety of different power management strategies that may beused to manage the charging of the base unit battery. In general, thegoal is to ensure that the base defibrillator unit 110 is alwaysfunctional—or in the event that its batteries are not recharged orreplaced when they should be, the defibrillator remains functional aslong as possible. It should be appreciated that the defibrillator unitwill consume some power during storage and thus its battery life is notindefinite. For example, the base defibrillator unit must periodicallywake up and perform required routine status checks. The frequency of thetests may vary widely, but in some embodiments, self-checks areperformed every day or every several days, on a weekly basis, on amonthly basis or at other appropriate intervals. In someimplementations, different level self-tests may be performed atdifferent frequencies. For example, some tests may be performed everyday (once each day), while others are performed weekly and still othersare performed monthly or at other appropriate intervals. In somecircumstance, some of the self-tests may even involve charging thedischarge capacitor to a level required for the delivery of adefibrillation shock which draws a non-trivial amount of power.

In some embodiments, the defibrillator controller 130 or a batterycharging/maintaining controller monitors the charge status of the powerstorage unit 170. This monitoring can be periodic or continuousdepending on the needs of any particular system. By way of example, suchmonitoring can be periodic when the defibrillator is not in use—as forexample by being a part of one of the regularly scheduled self-tests. Insome embodiments, the charge status checking is conducted morefrequently or continuously if/when the defibrillator is in use—as forexample during an emergency incident, a training session or duringvarious monitoring activities.

As mentioned above, a general goal is to ensure that the basedefibrillator unit 110 is always functional—or at least remainsfunctional as long as possible. Therefore, in some embodiment power willbe drawn from attached or connected devices to charge the power storageunit 170 when appropriate. One suitable approach for managing such powerdraws will be described with reference to FIG. 8.

In the embodiment illustrated in FIG. 8, base unit battery checks 401are periodically performed. These checks may be performed as part ofroutine self-tests at any desired frequency (e.g., daily, weekly or atany other desired frequency) and at any other time(s) deemed appropriate(e.g. any time the defibrillator is turned on for any purpose, any timea shock is administered, any time a device is initially connected to thedefibrillator via any of the connectors, etc. When a battery check isperformed, the power storage unit's current charge level is detected asrepresented by block 403. Any suitable charge level detection approachcan be used to determine the current charge level, as for example,reading the voltage level of a battery that constitutes the powerstorage unit.

The detected charge level is then compared to a charge thresholdrepresentative of a charge level below which the power storage unit 170should be charged. If the current charge level exceeds the chargethreshold, there is no need to recharge the power storage unit 170 atthis time. In such a circumstance, the current charge level is logged ina testing log as represented by block 408 and the battery check iscompleted. Conversely, if the charge level is determined to be below thecharge threshold in check 405, a determination is made as to whetherrecharging power is available from any attached (or otherwise connecteddevice) as represented by block 410.

For example, if one or more of an interface unit 200 and/or asupplemental battery pack 290 is attached, step 410 determines whethersuch a device has power that can be used to charge the power storageunit 170. If so, power is drawn from the attached device to charge thepower storage unit as represented by block 413. In the event that bothan interface unit 200 and a supplemental battery pack 290 are attachedto the base unit 110, charging power would typically be drawn first fromthe supplemental battery pack to the extent that such power isavailable. However, in other embodiments, the decision of which attachedunit to draw recharging power from first can involve other criteria suchas the relative charge levels of the interface unit vs. the supplementalbattery pack, etc. Of course, if other components are attached to thebase unit that are capable of supplying charging power, then power maybe drawn from those components as well, and if there are multipleattached devices, the order that the components are used to supplycharging power can be determined as appropriate for any particularsystem. Once the charging of the power storage unit is completed, thenthe charge status is logged as represented by block 408. The informationthat is logged, and the nature and structure of the logs that areutilized may vary based on the perceived needs of any particular system.By way of example, a charging log may be used to identify parameterssuch as the time that the charging occurred, the length of the chargingperiod, the before and after charge levels of the power storage unit,the device from which power was drawn (e.g., supplemental battery pack290, interface unit 200, etc.), the before and after charge levels ofthe batteries in the device that supplied the power, etc. If thecharging log is separate from the testing log, the fact that thecharging has occurred and any other desired parameters can be logged inthe testing log as well.

If there is not an attached device that can supply recharging power (asrepresented by the “no” branch from block 410, then a determination ismade regarding whether the charge level is below a designated minimumoperational charge level as represented by decision block 415. If so, abattery low status indictor (e.g. indicator 176(b)) may be activated toinform anyone observing the device that the battery is low and needs tobe recharged as represented by block 417. If an interface unit isprovided, the interface unit can be informed of the low battery statusand an appropriate message can be sent to the device's administratorinforming them of the need to charge the defibrillator.

Regardless of whether the battery charge level is determined to be lowor not, the current charge level and status is logged, as well as anydecision to activate the battery low status indicator as represented byblock 408.

It should be appreciated that the charge threshold utilized inrecharging decision 405 may be (but doesn't need to be) different thanthe minimum operational charge level utilized in battery low decision415 since they are potentially based on different criteria. The chargedecision may be based in part on charging considerations that promotelong battery life in addition to having enough energy to handle apotential cardiac incident. In contrast, the battery low check is basedprimarily on the latter.

Typically, when a device is plugged into the connector port 195, it isexpected that the connection will be more transitory in nature.Therefore, a different charging scheme may be used when a device isfirst plugged into the connector port 195 and described below withrespect to FIG. 9. However, if such a device remains connected for anextended period of time, power draws from the device can be manageddifferently, as for example in accordance with the approach describedabove with respect to FIG. 8 or in another appropriate manner.

Referring next to the flow chart of FIG. 9, a power draw managementscheme 420 appropriate for use when a device (such as a mobilecommunication device) is plugged into the connector port 195 will bedescribed. For the purpose of this explanation, it will be assumed thatthe connected device is a mobile phone, but the process may be generallysimilar for other connected devices taking into account the specificcapabilities of such devices.

When the presence of a connected device is detected, the defibrillatorcontroller 130 (or other charge management structure such as a batterycharging/maintaining controller) determines whether power is availablefrom the connected device (step 424). This can be accomplished byquerying the connected device, by receiving an initial message from theconnected device, or simply by detecting that power is present on theconnector's power line, or in any other suitable manner. If no power isavailable, then the charging power management query ends with respect tothe connected device. If power is available, then the defibrillatorcontroller 130 will determine what, if anything, the base unit wouldlike to do with the available power. How the available power will beused depends on an number of factors including whether an emergencysituation exists, the charge level of the base unit battery 170, thecharge level of the connected device 105, and the battery charge levelof any other connected components of the defibrillator system 100, suchas interface unit 200 and/or supplemental battery pack 290 if one orboth of those components are present.

If it is determined that power is available from the connected device,then a determination is made regarding whether the current use of thedevice is considered an emergency (or at least a potential emergency) asrepresented by decision block 427. The classification of a current eventas an emergency (or a potential emergency) can be made in a number ofdifferent way in accordance with the capabilities and desiredoperational characteristics of the defibrillator. For example, it may beconsidered a potential emergency any time a user activates the basedefibrillator unit by pressing power on button 183. Similarly, it may beconsidered an emergency or potential emergency if a user has indicatedan emergency by selecting an emergency button on a graphical userinterface displayed by a defibrillator app executing on the connecteddevice 105 or on the interface unit 200. In still other embodiments, itmay be considered a potential emergency any time a device is initiallyplugged into the base unit via connector 195. Of course, emergencysituations may be identified in a variety of other ways in otherembodiments.

If it is understood that the present situation is a potential emergencysituation (as represented by the “yes” branch from decision block 427),then a determination is made whether the discharge capacitor state isset to charge, as represented by decision block 429. If so, availablepower from the connected device 105 may be used to supplement thecharging of the discharge capacitor 150 as represented by block 431.This is desirable because in an emergency, operation of the base unit110 and charging the discharge capacitor as required is the highestpriority. In general, the device power may be used to supplement thedischarge capacitor charging until the charging is completed, at whichpoint the discharge capacitor state may be set to “charged.”

The decision of when to charge the discharge capacitor can be made in avariety of manners. In some implementations, the capacitor state is setto charge (and thus begin charging) as soon as it is determined that apotential emergency situation exists so that the defibrillator will beready to shock as soon as a shockable rhythm is detected (note thiscontrasts with conventional battery based defibrillators that often onlybegin charging the discharge capacitor after a shockable rhythm has beendetected). In other embodiments, charging may be initiated any time auser accesses the electrode pads 116—as for example by pulling a tab todraw the electrode pads out of the base unit housing 120. In otherembodiments, it may be considered a potential emergency and charging ofthe discharge capacitor may begin when the base unit 110 is initiallyturned on or when a mobile communication device 105 is initiallyconnected to the base defibrillator unit 110 as described. Some of thesescenarios are described in more detail in Applicant's U.S. Pat. No.10,029,109 which is incorporated herein by reference. The incorporated'109 patent also describes a variety of other triggers that may be usedto initiate charging of the discharge capacitor. It is noteworthy thatin the aforementioned circumstances, the charging begins before adetermination is made regarding whether a patient has a shockablerhythm. In still other embodiments, the discharge capacitor may becharged only after a shockable rhythm has been detected (i.e., using amore conventional discharge capacitor charging timing).

Charging (recharging) the discharge capacitor may also be automaticallyinitiated after any discharge occurs and/or at other suitable times (asfor example upon the detection of continuing shockable rhythms after adischarge has occurred). Of course, charging may be initiated in avariety of other circumstance as well, as for example, as part of atesting protocol or in other appropriate circumstances. Power from theconnected device can be used to supplement the charging of the dischargecapacitor in these circumstances as well if desired.

As previously noted, the ability to utilize power from a connectedmobile communication device to charge the discharge capacitors can be amajor benefit in that it can dramatically reduce the risk that adefibrillator may be unusable during an emergency due to dead batteries.In the (hopefully rare) event that the defibrillator battery 170 (andthe batteries of any other attached unit) is/are discharged to theextent that they cannot be used to charge the discharge capacitor 150, asmartphone, tablet computer or other portable device that can providepower can be plugged into the base unit 110 via connector port 195 andpower can be drawn from such a device as necessary to both (a) power thedefibrillator electronics (including any user interface items such asspeakers), and (b) supply power to charge the discharge capacitor 150.Since smartphones and other mobile communication devices are nearlyubiquitous at this stage, this feature can significantly reduce the riskthat a defibrillator system would be unusable during an emergency—evenif its batteries have not been maintained and charged as they weresupposed to be. This can help mitigate the risk that a publicdefibrillator might be unusable even if it had not been cared forproperly—which in practice has been shown to be a significant riskfactor in some installations.

When drawing power from a mobile communication device 105, it isimportant that the current drawn from the mobile communication devicenot exceed the maximum allowable power supply current for the connecteddevice. This is important because many mobile phones and other deviceswill cut off their power to external devices if the draw current isexceeded. The current regulator 143 can be used to ensure that thecurrent draw does not exceed the capabilities of the connected device.The incorporated '109 patent describes a number of current regulatingcircuits, including programmable circuits that can be used to controlthe current draw and to maintain a continuous current draw from theconnected device, and, if desired, maximize the current draw based onthe capabilities of the connected device.

Returning to FIG. 9, if no emergency situation is perceived at the timea mobile device is connected to the base unit via connector port 195 (asrepresented by the “no” branch from decision block 427, thedefibrillator controller 130 (or other charge management component)determines whether the base unit battery needs charging as representedby block 435. The same actions can be taken if the discharge capacitorstate is not set to “charge” or the discharge capacitor charging hasbeen completed, as represented by the “no” branch from decision block429.

If the base unit battery 170 needs charging, then power is drawn fromthe connected device to charge the base unit battery as represented byblock 437. It should be appreciated that the charge level threshold thatis used in determining whether to draw power from a connected device 105to charge the base unit battery may be (but does not need to be)different than the charge level threshold used in determining whether tocharge the base unit battery from an attached device. This is becauseconnections to devices via connector port 195 are generally expected tobe more transitory in nature, so an effort is made to use the connectionas an opportunity to charge the defibrillator system as a whole. Ofcourse, a variety of other factors including the charge level of theconnected device, can be considered when making the decision whether todraw current from the connected device to charge the base unit battery.

If the base unit battery doesn't need charging, or after the base unitbattery has been charged to the desired level (as represented by the“no” branch from decision block 435), a determination is made as towhether an attached interface unit 200 needs charging as represented byblock 440. If there is an attached interface unit and it needs charging,then power is drawn from the connected device to charge the interfaceunit as represented by block 442.

If no interface unit 200 is connected to the base unit 110 or if theinterface unit doesn't need to be charged or has already been charged(as represented by the “no” branch from decision block 440, adetermination is made as to whether an attached supplemental batterypack 290 needs charging as represented by block 444. If there is asupplemental battery pack 290 and it needs charging, then power is drawnfrom the connected device to charge the supplemental battery pack asrepresented by block 446. To the extent that there are any otherindependently battery powered components attached directly or indirectlyto the base unit, they can be charged using the same charging scheme. Inthe described embodiment, the base unit has the highest chargingpriority, the interface unit has the second highest priority and thesupplemental battery pack has a lower priority than either the base unitor the interface unit. The base unit has the highest priority because itis the potentially lifesaving component. The interface unit has thesecond highest priority because it provides very useful communicationand reporting functionality both during emergency situations and tofacilitate non-emergency management, maintenance and support of thedefibrillator.

In some embodiments, the charging power distribution is managed by thedefibrillator controller 130 or other charge management logic on thebase unit. Thus, the base unit can always interrupt a charging sessionif circumstances dictate. One such circumstance would be if it isdetermined that external power is needed for other purposes—as forexample to charge the discharge capacitor. Another example might be ifthe charge level of the connected device 105 falls below a designatedthreshold and the defibrillator doesn't absolutely need the power tofunction in an emergency situation. The triggers for such decisions canbe based on a wide variety of different criteria.

It is possible that a situation could arise in which the interfaceunit's battery is fully discharged at the time that a mobile device isconnected. In such circumstances, the defibrillator controller 130 canmake an affirmative decision to direct power to the interface unit 200at any time. In the illustrated embodiment, this is not first done inemergency situations if the power is being used to charge the dischargecapacitor. The reason for this is that again, the top priority is alwaysto make sure that the base unit is fully functional. However, in otherembodiments other priority schemes can be used. When power from theconnected device 105 is made available for other purposes, then thedefibrillator can grant operational power to the interface unit—whichallows the interface unit to function in its intended manner asrepresented by block 449.

The battery charge management described above has been explained usingthe constructs of flow charts. Thus, the processes have primarily beendescribed in a particular sequential order for the purposes of thisexplanation. It should be apparent that in many cases the specificordering is not critical. Some operations may be combined and others maybe parsed into multiple operations. The same functionality can also beobtained using different operations as well. In other embodiment,selected steps can be eliminated or modified to meet the needs of anyparticular application.

Status Indicators

In the embodiment illustrated in FIGS. 2A-2G, the base unit has a statusindicator interface 175 that includes a plurality of indicator lights176(a)-(d), as best seen in FIG. 2D. The specific indicators providedand the information conveyed by the specific indicators may vary withthe perceived needs of any particular embodiment. In the illustratedembodiment, each indicator 176 has an associated icon 178 thatgraphically indicates the relevance of the associated indicator. In theillustrated embodiment, the indicator lights 176 include: pad statusindicator 176(a); battery charge level indicator 176(b), warningindicator 176(c); and functionality indicator 176(d).

In one particular implementation, the pad status indicator 176(a) is litif/when the electrode pads 116 are not attached to give the user visualfeedback that the pads are missing or not attached. The battery lowindicator 176(b) is lit if/when the battery is low and needs to berecharged (or replaced—which is particularly relevant in embodimentsthat do not include a rechargeable battery). The warning indicator176(c) is lit (e.g. lit red) if a self-test of the base unit determinesthat the device is not functioning properly and should not be used.Functionality indicator 176(d) is lit green when the base unit isfunctioning properly and requires no attention or maintenance. Ifdesired, the functionality indictor 176(d) can be lit another color(e.g. yellow) and/or otherwise display a different signal (e.g. ablinking signal) if maintenance or other attention to the device isrecommended. Although specific types of indicators and specificindicator colors have been given for the purpose of illustration, itshould be appreciated that the nature of the specific indicators usedand/or the color and nature of the lighting of the various statusindicators when indicator lights are used, may vary in accordance withthe UI design goals.

In some embodiments, e-ink or an equivalent thereof may be used to showthe status. Specifically, a graphic may be configured to display themost recent functionality status. A desirable feature of using an e-inktype technology is that it only requires energy to change its state.Therefore, even if the device in inoperable for any reason, there isstill an appropriate indication of the device's status (e.g. a lowbattery, that the device isn't functional, etc.).

Defibrillator Control

In the embodiment illustrated in FIG. 2, the base unit is a fullyfunctional defibrillator. As such, the base unit provides all thecomponents and functionality needed for analyzing a patient's heartrhythms to determine whether they are experiencing a shockable cardiacrhythm, and if so, delivering a shock to a patient. It also has a userinterface suitable for instructing a user in how to operate the unit andreceiving any required user inputs (as for example, an initiate shockcommand if user input is required to actually deliver a shock).

In some embodiments, if, at the time of an emergency, an interface unit200 is attached to the base unit or a mobile communication device 105 isconnected to the base unit, the interface unit and/or mobile device donot control the operation of the base defibrillator unit 110 in any way.However, the base defibrillator may be configured to send instructionsto the attached or connected device as appropriate. There are severalpotential advantages to this approach. Most notably, it virtuallyeliminates the risk of a malfunction or failure to function that mightotherwise occur if the interface unit or the mobile device (asapplicable) were to be inadvertently disconnected during an incident. Italso virtually eliminates the risk that a failure of either theinterface unit or the mobile device would, in and of itself, render thedefibrillator unit unusable or ill-suited for its intended purpose.Thus, the described architecture can have significant advantages from asafety standpoint. Such an architecture also has potential advantagesfrom a regulatory review standpoint. Specifically, as mentioned above,in some jurisdictions, having the base defibrillator unit operatesubstantially the same way regardless of whether an interface unit isattached may reduce or eliminate the need for redundant full scaleapproval for the different configurations.

When an interface unit or a mobile communication device executing adefibrillator app is connected to the base unit during an emergencyincident, the base unit can send a variety of different informationand/or commands to such components. For example, the interface unit orconnected device can be instructed to display graphic and/or textualinstructions that are synchronized with and generally supplementinstructions provided by the base unit itself (which may take the formof audio instructions provided by the base unit). This can provide morecomfortable instructions to certain types of users than strictly audioinstruction and/or the rudimentary graphic that might be present on thebase unit alone.

During and/or after an incident, the base unit 110 can pass incidentinformation to the interface unit 200 or mobile communication device 105for forwarding, as appropriate, to emergency personnel via any availablecommunication link (e.g. a cellular, WiFi or other availablecommunication link). Such information can be very helpful to firstresponders and medical staff in evaluating a patient that hasexperienced a cardiac arrest.

In some alternative embodiments that incorporate a touch sensitivedisplay screen, the user may input commands to the defibrillator duringuse, such as an initiate shock command by pressing a GUI buttondisplayed on screen 220. Somewhat similarly, in some embodiments,selected functionalities of the defibrillator controller 130 can beoffloaded to the interface unit, when present, such as the shockablecardiac rhythm detection and/or other aspects of the defibrillatorcontrol functionality.

Synchronization of Instructions

As discussed above, when an interface unit 200 or a mobilecommunications device 105 with a defibrillator App installed thereon areconnected with the base defibrillator unit 110 during an emergency, theconnected device can be arranged to display graphic instructions to auser that match the instructions issued from the base unit (e.g. anaudio instruction issued by the base unit, although the base unit mayissue instructions in other formats as well). As the base unit givesdifferent instructions to the user, the graphic instructions displayedon the mobile communications device or interface unit change to matchthe instructions from the base unit.

The synchronization between the base unit and a connected interface unitor mobile communication device can be accomplished using a variety ofdifferent approaches. By way of example, one suitable approach isdescribed with reference to the flow chart of FIG. 11. In theillustrated embodiment, the base unit is configured to periodically sendstatus messages to any display device that is connected to the base unit(e.g., an interface unit 200 and/or a connected mobile device 105). Insome embodiments, the status messages are sent at regular intervals. Thespecific intervals used may vary but they are preferably fairlyfrequent. By way of example, frequencies on the order of several statusmessages per second works well (e.g. 3-20 Hz). In one specific example,status messages are sent every 0.1 seconds (i.e., at a frequency of 10Hz). When the base unit issues its instructions as audio instructions,new graphic displays are preferably well synchronized with thecorresponding audio instructions and the status message interval isselected to be short enough so that the graphic instructions do not lagnoticeably behind any audio instructions that may be given to provide apositive user experience.

The status message includes information about the base unit's currentstate. The specific status information sent may vary based on the needsof any particular application. By way of example, in some embodimentsthe status information reported may include one or more of: (i) the baseunit's operational state. The operational state may indicate, forexample, whether the base unit is activated in an emergency mode, is ina training mode, is in an active non-emergency mode, etc. In someembodiments, the operational state(s) may be parsed more narrowly suchthat the operational state indicates a current instructional state ofthe base unit. In other embodiments where the operational state is notindicative of the instruction state, the status information may include(ii) an indication of the current instruction (if any) that the baseunit is currently issuing or most recently issued to the user.

When the defibrillator has been activated in an emergency mode, thereported information may take the form of incident information, as forexample, one or more of: (iii) a timestamp or equivalent indicating whenthe base unit went into emergency mode; (iv) an indicator indicatingwhether any defibrillation shock(s) have been delivered, and if so, atimestamp or equivalent indicating the time at which each defibrillationshock was delivered; (v) the energy level of each shock delivered; (vi)the waveform associated with each shock delivered; (vii) the shock/noshock classification for any/all detected ECG analysis (and/or theassociated heart rhythm classifications if more detailed classificationis performed); (viii) a timestamp or equivalent associated with each ECGanalysis; (ix) recorded ECG samples; (x) whether or not the base unitsenses that the electrode pads are attached to the patient; and (xi) areport of any malfunctions that are detected during an activation of theAED.

When the defibrillator is not in an emergency mode, the reportedinformation may further include one or more of: (xii) battery chargelevel; (xiii) charging status (i.e. whether the base unit is beingrecharged or not); (xiv) firmware version installed; (xv) date and timeof latest firmware installation; (xvi) hardware version; (xvii) serialnumber; (xviii) a set of recent self-test results (e.g., the last 30days); and (xix) the base unit's functionality status.

Of course, the specific information that is conveyed as part of a statusmessage may vary widely, with more, less or different information beingtransmitted as appropriate for any particular implementation and/or thetransmitted information varying as appropriate based on the operationalstate of the defibrillator.

The compatible external device receives this status message and uses thedata therein to determine which graphic to display. One characteristicof the described embodiment is that the external device does not provideinstruction to the user that conflicts with the instruction(s) (audio orotherwise) received from the base unit.

In some embodiments, the compatible external device has a storedlibrary/dictionary/database which pairs the instruction states receivedfrom the base unit with specific graphics or graphic states of theexternal device. This helps ensure that the compatible external deviceprovides the correct graphic instruction. When the external devicereceives the status message from the base unit (which providesinformation about what instruction the base unit is currentlydelivering), the external device checks its database to determine whatgraphic instruction (if any) corresponds to the current state of thedefibrillator and should therefore be displayed. When a correspondinggraphic instruction is found, the external device's processor directsits display screen to display that corresponding graphic. With this ismind, in some embodiments, the refresh rate of the displayed graphicsmay be set based on the frequency at which the base unit sends statusupdates to the connected external device. The more frequent statusupdates are sent, the higher the refresh rate of the graphics displayed.

FIG. 12 diagrammatically illustrates a portion of a state table thatpairs defibrillator instruction states with specific graphics to bedisplayed on an interface unit and on a mobile device. The graphics maybe static images, short animations (e.g., GIFs), image sequences orother appropriate graphics, with or without accompanying text asappropriate for each particular instruction state. In many circumstancesthe graphics displayed on the interface unit may be very similar to thegraphics displayed on a mobile device—although that is not arequirement. For simplicity, the table of FIG. 12 illustrates only a fewrepresentative instruction states and it is expected that many morestates would be provided. Of course, the specific states shown are onlyrepresentative and may be widely varied to accommodate the desiredinstruction flow.

It should be appreciated that more complex algorithms/methods may beimplemented to account for outliers/false signals in the data stream.For example, if a connected device received a false/incorrect statusmessage that was corrupted in transit from the base unit, instead ofimmediately displaying the new corresponding (incorrect) graphic, it mayrequire multiple status messages to be received to re-affirm that it hasreceived the correct uncorrupted information from the base unit.

In some cases it may be beneficial for the connected device to knowahead of time what instruction the base unit plans to provide to theuser. This can be helpful because some display screens may have a delayassociated with displaying new graphics. To accommodate such planning,the status message may also include a next instruction indicator, aswell as an indicator of the timing at which such an instruction will begenerated. In embodiments that transmit the current state—the nextinstruction indicator can take the form of an indication of the nextexpected state. By receiving an indication of the base unit's nextinstruction, the external device can prepare ahead of time fordisplaying the next corresponding graphic.

Another noteworthy feature of supplemental graphics management relatesto the handling of a disconnection and/or poor connections during anemergency. In some embodiments, the connected external device isdisconnected from the base unit while displaying in-sync graphic duringan emergency, it will transition to a backup mode. In the backup modethe external device displays graphic instructions that do not conflictwith the instruction on the base unit.

The specific graphics and/or instructions displayed in the backup modemay vary based on design goals. For example, in one embodiment in whichthe display is relatively large, the connected external device revertsback to a single screen that displays all the instructions for use ofthe defibrillator in an ordered set of instructions. Such a display maybe textual and/or graphic instructions. In another embodiment, thebackup mode may be configured to allow the user to manually navigatethrough the graphic instructions; for instance, using front and backarrows. In another embodiment the screen may display text or graphicsthat indicate poor connection and that the user should follow the audioinstructions of the base unit. Of course, a variety of other specificgraphics and/or instructions may be provided in other implementations.

Referring next to FIG. 11, a representative in-sync graphics managementprocess 400 will be described. As suggested above, the base unit isconfigured to periodically send status messages to any display devicethat is connected thereto. Thus, the connected external device (e.g., aninterface unit 200 and/or a connected mobile device 105) willperiodically receive status messages from the base unit. When a statusmessage is received (as represented by the “Yes” branch from check 402),the logic will determine whether the status message contains aninstruction state as represented by check 404. If so, the logic willdetermine whether the currently displayed graphic corresponds to theinstruction state as represented by check 406. If so, the currentdisplay is maintained and the logic looks to receive the next statusmessage as represented by the “Yes” branch from check 406.Alternatively, if the current graphic does not match the instruction incheck 406, the logic checks a database to find a corresponding graphicas represented by block 408. If a corresponding graphic is found asrepresented by the “Yes” branch from check 410, that “new” graphic isdisplayed as represented by block 412. Thereafter, the logic looks toreceive the next status message.

As suggested above, in many implementations, the base unit is expectedto send updated status messages on a regular basis. If a status messageisn't received as expected (as represented by the “No” branch from check402), a check 421 is made as to whether the time since the last validmessage was received exceeds a designated allowable time period. Thismay be achieved by examining the time since the last status message wasreceived from the base unit. If a set amount of time passes (e.g. 1second, 0.5 sec, 0.1 sec, etc.) without receiving a status message fromthe base unit, then the external device infers that the connection withthe base unit has been lost or is poor, and it resorts to its backupmode as represented by block 423. If the backup mode is entered,appropriate backup graphics are displayed as previously discussed.Alternatively, if the allowable time period has not been exceeded, thelogic awaits the next incoming status message as represented by the “no”branch from check 421. In the illustrated embodiment, the timeout periodis longer than the expected status message reception interval. Althoughthis is not a strict requirement, such an approach provides a systemthat is robust enough to handle occasionally dropped or corruptedpackets.

It should be appreciated that a poor connection may also be inferredusing other metrics, such as corrupted status messages, un-readabledata, or a non-sensical series of instructions. Thus, if a receivedstatus message does not contain a readable instruction state (asrepresented by the “no” branch from check 404) or no graphic is foundthat corresponds to a received instruction state (as represented by the“no” branch from check 410), the logic can in-synch timeout logic cantreat those events as non-reception of a new instruction in the timeoutcheck 421. Thus, in some embodiments a last valid message received timeused in timeout check 421 may only be updated after validation of areceived instruction state in a status message. By way of example, suchvalidation may be based on confirmations from checks 406 or 412 or inother suitable manners.

It should also be appreciated that not all messages received by theconnected device during an emergency will necessarily be statusmessages. Rather, there may be a variety of other communications betweenthe units to facilitate communications with remote locations, thedisplay or delivery of detected EKG rhythms to responding emergency ormedical personnel, and/or any other information that may be helpful tomanagement and/or reporting of the incident.

Multimedia Use Scenario

As pointed out in the background section, AEDs have been deployed in awide variety of public and private locations so that they are availablein the event that a person in the vicinity goes in to cardiac arrest.Unfortunately, studies have shown that even when an AED is availablenearby, they are often not used when a cardiac arrest incident occurs.There are a number of factors that contribute to this underutilizationof AEDs. One significant usage barrier is tied to untrained peoplesreluctance use a device that they are unfamiliar with in what may be ahigh pressure situation that they are unfamiliar with and untrained for.Therefore, there are a number of organizations that try to educate thegeneral population on basic lifesaving techniques such as CPR and theuse of AEDs.

The display screen on the interface unit 200 can have a relatively highresolution, as for example, on par with the resolution of displayscreens used in mobile communication devices. The interface unit'sprocessor 210 may have significant computing resources and the memory213 may be large enough to support the storage of video files. Thesecapabilities support an

AED training scenario that is quite different than existing trainingprograms. Specifically, AEDs are often mounted in cabinets in fairlyhigh traffic locations in public places. When a charging dock and aninterface unit 200 is provided, the interface unit can be configured todisplay AED training videos while the defibrillator is operating in astandby (non-emergency) mode. In some embodiments, the training videosmay be interactive in nature. This can be a powerful training tool whenan interface unit 200 is installed at a public place where passersby mayhave some idle time and can engage the training videos and learn aboutresponding to cardiac arrest incidents and the use of AEDs.

In other embodiments, an interested passerby may be able to plug theirown mobile communication device in or communicate with the defibrillatorover a wireless link (e.g. Bluetooth). This permits cardiac arrestresponse training that through the use of the learners own personaldevice which is believed to have the potential to be a powerfuleducational tool.

Inductive Charging

In many of the embodiments described above, a connector or a connectorcable is utilized to electrically couple the base defibrillator unit 110to other components such as the interface unit 200, mobile device 105,the battery pack 290 and/or any other components. However, in otherembodiments, such connections can be entirely wireless. As discussedabove, when the base unit includes an inductive charging receptor, thebase unit can be powered, charged and/or recharged using an inductivecharging station on a dock suitable for storing the base unit. The samereceptor may be used to receive power from a supplemental battery pack,a mobile device, an interface unit or any other component that supportswireless charging.

It is expected that wireless charging will become a common feature insmartphones and other mobile communication devices in the near future.When a mobile device is configured to support wireless inductivecharging, it can readily be adapted to deliver energy to peripheraldevices using the same coils and circuitry. The inductive chargingreceptor on the base defibrillator unit can readily be adapted toreceive power from smartphones and other similar devices through thewireless charging interface.

In some embodiments, communications between the base unit and otherdevices may also be accomplished wirelessly. For example, in someembodiments, the base unit and the peripheral devices may each haveBluetooth (or other short range communication) capabilities to supportBluetooth or other appropriate communications between the devices. Instill other embodiments, the wireless communications may be accomplishedusing the inductive charging system.

Another Embodiment

FIGS. 13A-13D are a set of views of a modular defibrillator 500 inaccordance with yet another embodiment that has a somewhat differentform factor than the previously described embodiments. The version showntherein includes a base unit 510 having an interface unit 600 installedtherein. In the illustrated embodiment, the base unit 510 includes abase unit housing 511 that has a generally square or rectangularfootprint with rounded corners and rounded edges. An electrode padcartridge 517 is slideably received in cartridge recess that opens in atop end 512 of the base unit housing 511. The cartridge 517 includes apull tab 518 that can be pulled to draw the cartridge from the housing511. FIG. 14 illustrates the cartridge in an extended position where ithas been pulled out to provide access to the electrode pads.

The bottom end 513 of the base unit housing 511 includes a power button183, charging connector/contacts 597, a mobile connector port 195, and(optionally) a language selector 598 as best seen in FIG. 13C and/or apediatric selector 599. The illustrated embodiment is a fully automatedAED and thus no separate shock button in provided—however in otherembodiments, a manual shock button may also be provided. In theillustrated embodiment, the connector port 195 is a USB-C connector portalthough a wide variety of other connectors can be used in otherembodiments. The charging contacts 597 are surface contacts althoughagain, a wide variety of other charging connector interfaces can be usedin other embodiments.

The language selector 598 provides a mechanism by which a user canselect the language for audio and textual instructions, prompts andmessages. In the illustrated embodiment, the language selector 598 takesthe form of a push button, but in other embodiments a toggle switch, twoor more push buttons or a variety of other mechanisms can be used as thelanguage selector 598. When a particular language is selected, thedefibrillator controller directs all audio and graphic instructions tobe presented to the user in the selected language.

The pediatric selector allows the user to identify the patient as apediatric patient. In some embodiments, the discharge capacitor 150 ischarged to a lower charge level when the pediatric mode is selected sothat a lower energy shock is delivered. In other embodiments, analternate “pediatric” path (not shown) is provided in the dischargecircuit that introduces a resister in series with the patient to therebylimit the energy delivered to the patient. In still other embodiments,separate pediatric pads may be provided or other approaches may be usedto limit the discharge appropriately for pediatric patients.

As best seen in FIG. 14, in the illustrated embodiments, the electrodepad cartridge 517 takes the form of a drawer that can be drawn from thetop end 512 of housing 511 by pulling on pull tab 518. Once thecartridge 517 is withdrawn from the housing, its contents can be readilyaccessed. Electrode pads (not shown) are stored within the cartridge517. In some embodiments other items that might be useful at the time ofan incident such as scissors 531, a razor, etc., may also be storedwithin the cartridge 517. Storage the scissors and/or other useful itemsinternally in the cartridge so that they are readily accessible and arenot easily lost or misplaced or accidently left behind in an accessorybag can help ensure that they will be available when needed.

In some embodiments, the pull tab 518 is an extension of a peelableflexible cartridge cover 519 that is adhered to a base 521 of thecartridge. Such a cover 519 can readily be peeled from the cartridgebase 521 to expose/access the electrode pads. In some embodiments, theflexible cover 519 seals (or hermetically seals) the cartridge. Ofcourse a wide variety of other cartridge geometries are possible. By wayof example, in some embodiments, (not shown) the pull tab 518 may beattached to or integrally formed with the cartridge base. In someembodiments the cover 519 may be eliminated so that the cartridge base521 takes the form of an open drawer. The defibrillator may also includeone or more cartridge sensors (not shown) that sense when the electrodepad cartridge 517 is securely connected and when the cartridge has beenremoved (withdrawn) from the housing. The electrode pads areelectrically connected to the base unit and remain connected when thecartridge is withdrawn from the housing.

An alternative cartridge design is illustrated in U.S. ProvisionalApplication No. 62/737,032, filed Sep. 26, 2018, which is incorporatedherein by reference.

The base unit housing 511 may also include speaker perforations 181which provide an opening through which sound from an adjacent speaker(s)180 may pass. In the illustrated embodiment, the speakers are located onthe top side of the defibrillator unit 500 so the speaker perforationsare on the top end 512 of the housing 511. However, it should beappreciated that the speakers (and any associated speaker perforations)can be positioned at any suitable location on the base unit.

As best seen in FIGS. 15A and 15B, the base unit housing 511 includes amodule receptor 508 on its front face. The floor 509 of the modulereceptor 508 includes an interface connector 190 that facilitateselectrically connecting an interface unit 600 to the base unit 510. Whenan interface unit 600 is used, the interface unit may be securelymounted in the module receptor 508 by latches or other suitablemechanisms. When an interface unit 600 is not used, a card or placard505 (FIG. 16) or other suitable item can be placed in the modulereceptor to provide potentially useful information to a user—as forexample, signage indicating that the device is an AED, operatinginstructions and/or any other information deemed useful. The placard maybe held in place by the same latching mechanism as would be used tosecure an interface unit 600 to the base unit 510. FIGS. 13A-Dillustrates a defibrillator 500 having an interface unit 600 installedin the base unit's module receptor 508. FIG. 14 illustrates thedefibrillator 500 having a placard 505 placed in the module receptor508.

A latching and registration arrangement suitable for detachable couplingthe interface unit 600 (or a placard 505) to the base unit 510 is shownin FIGS. 15A-15C. In the illustrated embodiment, the base unit 510includes a registration element 545, a pair of notch recesses 547 onopposite sides of the registration element 545 and a pair of catchrecesses 549 on an opposing end as the registration element. Theregistration element 545 and notch recesses 547 are best seen in FIG.15A, whereas catch recesses 549 are best seen in FIG. 15B. The inserteddevice (e.g., interface unit 600 or placard 505) includes a registrationslot 645, a pair of projections or nubs 647, and a pair of latches 649.The registration slot 645 and latches 649 are best seen in FIG. 15C. Theprojections/nubs 647 are best seen in FIG. 15B. The projections/nubs 647are positioned at the bottom edge of the inserted device and arearranged to be inserted into the recessed notches on the bottom end wallof module receptor 508 with the registration slot 645 extending over andreceiving registration element 545. In the illustrated embodiment,registration element 545 takes the form of a ridge type projection thatextends upward from the floor 509 of module receptor 508 at the bottomend of the receptor. The registration element/notch configuration helpsensure that the inserted device is inserted into the module receptorwith the correct orientation. The latches 649, which are on the top endof the inserted device are arranged to snap into catch recesses 549 onthe top end of the module receptor. As can be seen, the illustratedlatching arrangement securely couples the inserted device (e.g.,interface module 600, placard 505) into the module receptor 508 and canhold the inserted device in place regardless of whether the coupleddevice is held upside down, jostled or dropped, or otherwise handled ina rough manner.

As best seen in FIG. 15A, the top edge of base unit housing 511 may havea pair of pinholes through which pins may be inserted to release thelatches 649 by elastically pushing catch portions of the latches out ofthe catch recesses 549. In some embodiments a specialized release toolmay be provided to make it easier to release the device. For example therelease tool may take the form of a bar having a pair of parallel pinsthat are spaced the same distance apart as pinholes 551 that extend toone side of the bar. Such a tool can be used to quickly release theinterface unit or other inserted device from the base unit 510.

As previously mentioned, the floor 509 of the module receptor 508 mayinclude a set of surface contacts that serve as interface connector 190.The interface module 600 may include a connector 240 that is arranged toengage interface connector 190 to electrically couple the interface unitto the base unit as previously described. When the interface unitcommunicates with the base unit wirelessly (as for example, usingBluetooth communications), the connectors 190 and 240 can optionally beeliminated if power cannot be transferred between the devices, orreduced to a simple power connector if only power (and no data) istransferred through those connectors.

Although specific latching, registration and electrical connectorstructures are shown, it should be appreciated that the geometry,orientation and configuration of any of these elements can be widelyvaried while accomplishing the same intended functions.

In various illustrated embodiments, the interface units 200 and 600 allinclude both a display screen that can be used to display graphics andconnectivity features that facilitate communications with externaldevices such as a remotely located server. However, it should beappreciated that in some alternative embodiments the interface unit mayhave more limited, broader or simply different functionality. Forexample, in some embodiments, the interface unit may be arranged tofacilitate Wi-Fi or cellular communication, but not include a displayscreen. In other embodiments, the interface unit may include a displayscreen and be arranged to provide in-synch graphical instruction duringan emergency, but may not facilitate remote communications. In stillother embodiments, a portable charger (supplemental battery pack) or acombined interface unit/portable charger may be inserted into the modulereceptor 508. Of course a variety of other functionality mayadditionally or alternatively be provided by the interface unit or othertype of device inserted into the module receptor 508 or otherwiseattached to a base defibrillator unit. In some embodiments, thedefibrillator includes sensors that detect the attachment of aninterface unit or a portable charger and the defibrillator controllercan communicate with the attached device to determine its identity orfunctionality.

Like some of the previously discussed embodiments, the base unit may besecured to charging station dock to facilitate charging thedefibrillator's battery. The charging station may be a wall mountedcharging station, a desktop charging station or any other appropriateform factor. The charging stations may include clips, pockets,connectors or other suitable attachment mechanisms to firmly hold thedefibrillator unit 500 in place when it is docked at the chargingstation. In some embodiments, the side walls of the base unit housingmay include recesses, nubs or other projections that may be engaged bycomplementary mechanisms such as spring clips on the charging station tohelp secure the base unit when it is docked at the base station.

Other Features

In many of the embodiments described above, an intelligent device suchas an interface unit 200 or a smart phone or other mobile communicationdevice, is, or can be connected either wirelessly or through a wiredconnection to the base unit. Instructions can be sent from the base unitto the connected device and the connected device may providesupplemental functionality, as for example, calling emergency services(e.g., 911 in the U.S.). In some embodiments, care is taken to ensurethat the connected device does not alter the function of the base unitin any way. For example, if the base unit issues audio instructions whenit is not connected to an external device, it would still issue thosesame audio instructions when connected to an intelligent device, even ifthe intelligent device is presenting supplemental graphics or othermaterials synchronized with instructions issued by the base unit. Suchan approach is believed to have significant advantages from both asafety (and regulatory review) standpoint in that the base unitfunctions the same regardless of what other power sources orsupplemental interface devices are connected thereto.

In most of the embodiments discussed above, the interface unit does notcover the UI buttons on the base unit. In other embodiments, theinterface unit may include one or more appropriately marked or labeledskin(s) that covers the one or both of the base unit's user inputbuttons 183, 186, so long as such skins do not impede the functionalityor accessibility of the buttons. In other embodiments, structures otherthan skins can also be used to cover the user input buttons—so long asthe buttons remain functional and easily activated.

In some embodiments, the base unit is compatible with a pouch which maybe used to store accessories that might be useful in connection with theuse of the defibrillator. Such accessories might include items such asscissors, razors, USB cords, an extra set of electrode pads, and otheraccessories. In still other embodiments, the pouch can hold the primaryelectrode pads. In some embodiments the pouch takes the form of a coversleeve, which fits snugly around the base unit itself. The cover sleevecan come pre-stitched in the side, bottom, or top of the unit itself orit may come as an add-on that wraps completely around the base unit.Like the other components, it is important that the pouch does not blockthe power button, shock button, electrode pads, or other criticalcomponents of the system. In still other embodiments, the base unititself, or the interface unit, or any other connected device may housescissors and/or razors and/or any other items of interest.

In still other embodiments, a CPR feedback mechanism may be incorporatedinto the interface unit or be provided as a separate module. The CPRfeedback mechanism may include, for example, a pad that is placed overthe patient's heart during CPR and detects the depth of compressionsduring CPR. Such information can be used by the interface unit or CPRmodule to provide user feedback on the CPR that is beingadministered—e.g., press harder, pressing too hard, slow down, speed up,etc.

From the foregoing, it should be apparent that the described system ishighly modular and that a variety of components including the interfaceunit, the supplemental battery pack, a wireless charging station, astorage cradle, a wall mount, a desk mount, and/or other accessories canall attach directly or indirectly to the base unit. Other devices suchas smartphones and other mobile communication devices can also readilybe connected to the base unit to further extend the capabilities of thedefibrillator.

Although only a few embodiments of the invention have been described indetail, it should be appreciated that the invention may be implementedin many other forms without departing from the spirit or scope of theinvention. For example, although particular logic and electroniccircuitry has been described to facilitate explanation of variousaspects of the invention, it should be appreciated that the actualelectronic circuits, algorithms and/or logic used to accomplish thedescribed functions may vary widely and are in no way intended to belimited to the accompanying diagrams, figures and flow charts. Rather,various components, steps and functions may be reordered, altered, addedor deleted in accordance with designer preferences and/or the needs ofany particular implementation.

The use of a smartphone based app as a user interface has an importantadvantage of familiarity to the user. That is, since most users interactwith apps on their phone every day, packaging the user interface in anapp makes people feel more comfortable when responding to an emergencysituation that requires use of an AED.

The app can also be configured to provide metrics related to thedefibrillators' use. This data can further be used to infer aboutgeneral AED performance, perform studies on people's reaction toemergency situation, and ultimately inform redesigns of the product.

The various control methods described herein can be implemented usingsoftware or firmware executed on a processor of the defibrillatorcontroller or any other processor suitably programmed with appropriatecontrol algorithms. Alternatively, when desired, the functionality canbe implemented in the form of programmable logic (e.g. programmablelogic arrays, FPGAs, etc.) or using application specific integratedcircuits (ASICs) or a combination of any of the foregoing.

When software or firmware algorithms are used, such algorithms may bestored in a suitable computer readable medium in the form of executablecomputer code (programmed instructions) with the operations beingcarried out when a processor executes the computer code. Thedefibrillator or the defibrillator controller may include memorysuitable for storing all of the code that is to be executed by thedefibrillator and the interface unit and the mobile device each includememory suitable for storing the defibrillator app and/or other softwareor firmware to be executed thereon.

More generally, the described mechanical design allows for modularcomponents to be readily added and integrated with the maindefibrillator circuitry and mechanical design.

The described modular defibrillator architecture is particularly welladapted for use in automated defibrillators that are suitable for use bylay operators and thus is very well suited for use with both: (a) fullyautomated defibrillators in which a shock is automatically delivered bythe defibrillator in appropriate situations without any user input afterthe electrode pads have been applied; and (b) semi (partially) automateddefibrillators in which the defibrillator determines whether a shockablerhythm exists and the timing of when to deliver the shock, but a userinput initiate shock command is required to actually initiate the shock.Although the inventions have been described primarily in the context ofautomated defibrillators, it should be appreciated that the describedapproaches can also be used in manual defibrillators and hybriddefibrillators that can be used in two or more different operationalmodes (e.g., manual, fully automated, semi-automated, etc.). Indeed, amanual defibrillator app executing on either the defibrillator interfaceor a personal mobile communication device can be an excellent interfaceplatform for a manual defibrillator or a manual defibrillationoperational mode. In some embodiments, the operational mode of thedefibrillator may be changed via software updates. In such embodiments,a responsible party may elect for a defibrillator placed in a particularlocation to operate in a particular manner—e.g., fully automated,semi-automated or manual—and the software on the base unit can beupdated to facilitate the desired operational mode.

The steps associated with the various methods described herein may vary.Steps may be changed, reordered, added, and removed without departingfrom the spirit or the scope of the present invention.

Although the described form factors provide compact designs making thedefibrillator itself highly portable and easy to use, it should beappreciated that a variety of different form factors may be used inalternative embodiments. Similarly, although specific electroniccircuits, defibrillator control logic and user interfaces have beendescribed, it should be appreciated that all of these features may bewidely varied. Therefore, the present embodiments should be consideredillustrative and not restrictive and the invention is not to be limitedto the details given herein, but may be modified within the scope andequivalents of the appended claims.

What is claimed is:
 1. A defibrillator comprising: a defibrillatorcontroller; a discharge capacitor unit configured to store and dischargesufficient energy to deliver a defibrillation shock to a patient;charging circuitry configured to charge the discharge capacitor unit toa voltage suitable for delivery of the defibrillation shock; dischargecircuitry suitable for discharging the discharge capacitor unit todeliver the defibrillation shock; a battery configured to power thedefibrillator and to provide power for charging the discharge capacitorunit; a USB connector port; a battery charging controller electricallyconnected to the USB connector port and configured to facilitatecharging the battery using power drawn from a portable external devicethrough the USB connector port when the portable external device iselectrically connected to the defibrillator via the USB connector port;and a bypass circuit electrically coupled to the USB connector port andconfigured to provide power received from the portable external devicethrough the USB connector port directly to the charging circuitrywithout passing through the battery charging controller to facilitatecharging the discharge capacitor unit using power drawn through the USBconnector port when the portable external device is electricallyconnected to the defibrillator via the USB connector port duringcharging of the discharge capacitor unit.
 2. A defibrillator as recitedin claim 1 wherein the bypass circuit includes a draw regulatorconfigured to regulate the power drawn from the portable external deviceto prevent the power drawn from the portable external device fromexceeding a designated current delivery threshold associated with theportable external device.
 3. A defibrillator as recited in claim 1wherein the bypass circuit alone is used to charge the dischargecapacitor unit when the external device is connected to thedefibrillator during charging of the discharge capacitor unit and thebattery is fully discharged.
 4. A defibrillator as recited in claim 1wherein the portable external device that delivers power to the bypasscircuit is a battery powered device.
 5. A defibrillator as recited inclaim 4 further comprising a defibrillator housing that contains thedefibrillator controller, the discharge capacitor unit, the chargingcircuitry, the bypass circuit and the discharge circuitry, and whereinthe USB connector port is exposed externally on the defibrillatorhousing.
 6. A defibrillator as recited in claim 1 further comprising apair of defibrillator electrode pads suitable for attachment to thepatient to deliver the defibrillation shock, and wherein the bypasscircuit is configured to facilitate charging the discharge capacitorunit while the defibrillator is in emergency use with the defibrillatorelectrode pads coupled to the patient at a location at which power froma power grid is not readily available.
 7. A defibrillator as recited inclaim 1 wherein the portable external device that provides power to thebypass circuit is a cellular phone or other mobile communication device.8. A defibrillator as recited in claim 1 wherein the portable externaldevice that provides power to the bypass circuit is a supplementalbattery pack mounted on and detachably coupled to the defibrillator. 9.A defibrillator as recited in claim 1 further comprising a secondconnector for electrically coupling a second external device to thedefibrillator, the second connector being different than the USBconnector port and configured to receive power from the second externaldevice that can be used selectively to: (i) help charge the dischargecapacitor unit; or (ii) recharge the defibrillator's battery.
 10. Adefibrillator as recited in claim 9 wherein the second external deviceis a dedicated interface unit that has no substantial function otherthan to operate in conjunction with the defibrillator but is notrequired for the defibrillator to operate properly.
 11. A defibrillatoras recited in claim 1 wherein the defibrillator is fully functionalwithout the presence of the portable external device and does notutilize any control instructions from the portable external deviceduring emergency use of the defibrillator.
 12. A defibrillator asrecited in claim 1 wherein the bypass circuit is further configured toprovide power received through the USB connector port from the portableexternal device to the charging circuitry in parallel with powerreceived from the battery to facilitate charging the discharge capacitorunit when the portable external device is connected to the defibrillatorduring charging of the discharge capacitor unit.
 13. A defibrillator asrecited in claim 1 wherein the bypass circuit is suitable for deliveringpower to the charging circuit while the defibrillator is being used inthe field and the portable external device is not connected to a powergrid.
 14. A defibrillator system comprising: a defibrillator as recitedin claim 1, wherein the defibrillator is a base defibrillator unit thatconstitutes a fully functional defibrillator that is independentlycapable of determining when a defibrillation shock is advisable anddelivering the defibrillation shock; and a supplemental battery packmounted on and detachably attached to the base defibrillator unit suchthat the base defibrillator unit and the attached supplemental batterypack form a unitary unit that may be carried together as a portablesystem; and wherein the defibrillator's battery charging controller isconfigured to utilize power from the supplemental battery pack torecharge the defibrillator's battery.
 15. A defibrillator system asrecited in claim 14 wherein the battery charging controller isconfigured to draw power from the supplemental battery pack to chargethe defibrillator's battery when it is determined that a charge level ofthe defibrillator's battery has fallen below a designated chargethreshold.
 16. A defibrillator system as recited in claim 14 wherein thesupplementary battery pack is the portable external device.
 17. A methodof using a defibrillator as recited in claim 1 comprising: electricallyconnecting the portable external device to the defibrillator via the USBconnector port; and charging the discharge capacitor using energy drawnfrom the portable external device during emergency use of thedefibrillator.
 18. A defibrillator comprising: a defibrillatorcontroller; a discharge capacitor unit configured to store and dischargesufficient energy to deliver a defibrillation shock to a patient;charging circuitry configured to charge the discharge capacitor unit toa voltage suitable for delivery of the defibrillation shock; dischargecircuitry suitable for discharging the discharge capacitor unit todeliver the defibrillation shock; a battery configured to power thedefibrillator and to provide power for charging the discharge capacitorunit; a power receiver configured suitably to receive electrical powerfrom a battery powered portable external device during emergency use ofthe defibrillator; a battery charging controller electrically connectedto the power receiver and configured to facilitate selective charging ofthe battery during the emergency use of the defibrillator using powerreceived from the battery powered portable external device through thepower receiver; and a bypass circuit electrically coupled to the powerreceiver and configured to selectively provide power received from thebattery powered portable external device to the charging circuitrywithout passing through the battery charging controller to facilitateselectively charging the discharge capacitor unit using power drawnthrough the power receiver during the emergency use of thedefibrillator.
 19. A defibrillator as recited in claim 18 wherein thebattery powered portable external device that delivers power to thebypass circuit is a mobile communication device.
 20. A defibrillator asrecited in 18 wherein the power receiver is selected from the groupconsisting of: a USB connector; a lightning connector; and an inductivecharging receptor.
 21. A defibrillator as recited in claim 18 whereinthe bypass circuit includes a draw regulator configured to regulate thepower drawn from the battery powered portable external device to preventthe power drawn from the battery powered portable external device fromexceeding a designated current delivery threshold associated with thebattery powered portable external device.
 22. A defibrillator as recitedin claim 18 further comprising: a defibrillator controller configured todirect charging and discharge of the discharge capacitor; and a switchthat is controlled by the defibrillator controller, the switch having afirst state that electrically connects the bypass circuit, and not thebattery, to the charging circuitry to facilitate charging the dischargecapacitor from the portable external device, and a second state thatelectrically connects the battery, and not the bypass circuit, to thecharging circuitry to facilitate charging the discharge capacitor fromthe battery, whereby only one of the bypass circuit and the battery maydeliver power to the charging circuitry at any given time.
 23. Adefibrillator comprising: a defibrillator controller; a dischargecapacitor unit configured to store and discharge sufficient energy todeliver a defibrillation shock to a patient; charging circuitryconfigured to charge the discharge capacitor unit to a voltage suitablefor delivery of the defibrillation shock; discharge circuitry suitablefor discharging the discharge capacitor unit to deliver thedefibrillation shock; a battery configured to power the defibrillatorand to provide power for charging the discharge capacitor unit; a powerreceiver configured suitably to receive electrical power from anexternal device; a battery charging controller electrically connected tothe power receiver and configured to facilitate selective charging ofthe battery using power received from the external device through thepower receiver; and a bypass circuit electrically coupled to the powerreceiver and configured to selectively provide power received from theexternal device to the charging circuitry without passing through thebattery charging controller to facilitate selectively charging thedischarge capacitor unit using power drawn through the power receiver.24. A defibrillator as recited in claim 23 further comprising a switchhaving a first state that electrically connects the bypass circuit, andnot the battery, to the charging circuitry to facilitate charging thedischarge capacitor from the portable external device, and a secondstate that electrically connects the battery, and not the bypasscircuit, to the charging circuitry to facilitate charging the dischargecapacitor from the battery, whereby only one of the bypass circuit andthe battery may deliver power to the charging circuitry at any giventime.
 25. A defibrillator as recited in claim 23 wherein the bypasscircuit includes a draw regulator configured to regulate the power drawnfrom the external device to prevent the power drawn from the externaldevice from exceeding a designated current delivery threshold associatedwith the external device.